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Mathematics Grade-9 Aptitude Assessment Tests This book contains nine Aptitude Assessment Tests and is useful for students and learners who are preparing for Standardized Tests, Achievement Tests, Aptitude Tests and other competitive examinations all over the world Er. Sanjiva Dayal, B.Tech. (I.I.T. Kanpur) First Edition 2015 Sanjiva Dayal Classes For Mathematics Head Office: A-602, Twin Towers, Lakhanpur, Kanpur-208024, INDIA. Phone: +91-512-2581426. Mobile: +91-9415134052. Email: sanjivadayal@yahoo.com. Website: www.amazon.com/author/sanjivadayal. ISBN-13: 978-1511696920 ISBN-10: 1511696923 Copyright © Sanjiva Dayal, Author All rights reserved. No part of this publication may be reproduced, distributed or transmitted in any form or by any means electronic, mechanical, photocopying and recording or otherwise, or stored in a database or retrieval system, including, but not limited to, in any network or other electronic storage or transmission, or broadcast for distance learning without the prior written permission of the Author. i ABOUT THE AUTHOR Indian Institute of Technology Joint Entrance Examination (IIT-JEE) is considered to be one of the toughest competitive entrance examinations in the world with success ratio well below 1%. The author of this book Sanjiva Dayal was selected in IIT-JEE in his first attempt. After completing B.Tech. from IIT Kanpur, since the last more than 25 years, he has been teaching IIT- JEE Mathematics to the students aspiring for success in IIT-JEE and other engineering entrance examinations with an objective to provide training of the highest order by way of specialized and personalized oral coaching, teaching, training, guidance, educational facilities including tutorials, tests, assignments, reading materials etc. and all such facilities which are helpful to the students seeking admission in the IIT and other Engineering Institutes of India. His excellent teaching and result-oriented methods have combined to produce outstanding performance by his students in the past years. A large number of his students were selected in their First Attempt with top ranks. Most of his students have secured admission in the IIT and other Engineering Institutes of India and they are doing well in their engineering education and professional career also. Conceptual understanding of Mathematics provided by him not only helps his students to do well in the IIT-JEE and other engineering entrance examinations but also helps them to do well in their engineering studies where they are pitted against the best students of the country and competition is much more intense. ii ACKNOWLEDGEMENTS I thank the Almighty God for my very existence and for providing me the opportunity and resources to write this book. Mother is the first teacher and father is the second teacher. My respects and deepest gratitude to my mother Late Pushpa Dayal, my father Late Chandra Mauleshwar Dayal, my grandfather Late Lakshmeshwar Dayal, my grandmother Late Sarju Dayal, my maternal grandfather Late Ranbir Jang Bahadur and my maternal grandmother Late Chandra Kishori Bahadur who are no longer in this world but their blessings are always with me. I am extremely thankful to all my school teachers and all my IIT Kanpur Professors who have taught and trained me. I am also extremely thankful to all my batch mates in IIT Kanpur because studying and training with such brilliant persons was an amazing experience for me which will be cherished by me throughout my life. I am also extremely thankful to all my students because teaching and interacting with such brilliant minds has been an amazing learning experience for me which will be cherished by me throughout my life. I am also extremely thankful to my wife Dr. Vidya Dayal, my sister Ms. Smita Prakash and my niece Ms. Somya Prakash for their love, cooperation and moral support. I am also extremely thankful to my childhood friends Mr. Navneet Butan, Mr. Pankaj Agarwal, Mr. Akhil Srivastava and Mr. Subir Nigam for their love, cooperation and moral support. I am also thankful to all other persons who have ever helped me directly or indirectly. I am also thankful to my student Mr. Ashutosh Verma for his help and efforts in publishing this book. Place: Kanpur, India. Date: 12thApril, 2015. Sanjiva Dayal iii PREFACE TO THE FIRST EDITION 2015 "If there is a God, he's a great mathematician."~Paul Dirac "How is an error possible in mathematics?"~Henri Poincare "Go down deep enough into anything and you will find mathematics."~Dean Schlicter This book contains nine Aptitude Assessment Tests and is useful for students and learners who are preparing for Standardized Tests, Achievement Tests, Aptitude Tests and other competitive examinations all over the world. All readers and students are requested and welcome to send their feedback, comments, corrections, suggestions, improvements, mathematical theory and questions on my email ID sanjivadayal@yahoo.com. This will help in continuous improvement and updation of this book. All readers and students are invited to join me as friends on Facebook at URL www.facebook.com/sanjiva.dayal and they are also invited to join my Facebook Group "Mathematics By Sanjiva Dayal". Place: Kanpur, India. Date: 12th April, 2015. Sanjiva Dayal iv CONTENTS About The Author i Acknowledgements ii Preface iii Test Paper No. 1 1.1 Test Paper No. 2 2.1 Test Paper No. 3 3.1 Test Paper No. 4 4.1 Test Paper No. 5 5.1 Test Paper No. 6 6.1 Test Paper No. 7 7.1 Test Paper No. 8 8.1 Test Paper No. 9 9.1 GRADE 9 ASSESSMENT OF MATHEMATICS Multiple-Choice Questions: Question no. 1.1 to 1.12 Short-Answer Questions: Question no. 2.1 to 2.5 Tasks: Question no. 3.1 to 3.3 Test Paper No. 1 PREPARED BY: Sanjiva Dayal (sanjivadayal@yahoo.com) Multiple-Choice Questions 1.1 A car is moving on a circular path with a constant speed. The distance of the car from the center of the circular path is d. Which of the following graph shows the relationship between d versus time? Circular path Car Center of the circular path (a) time (b) time (c) time (d) time The line joining the points x, x 2 and 2x 1,x 1 has slope equal to 1. What is the equation of this line? (a) y x 3 (b) y x 4 (c) y 2x 1 (d) y x 2 1.3 Which of the following pair of lines are the diagonals of a rhombus? (a) 2x 3y 5 0 and 2x 3y 5 0 (b) 3x 4y 5 0 and 4x 3y 7 0 (c) 3x 4y 5 0 and 3x 4y 2 0 (d) 2x 3y 1 0 and 4x 6y 1 0 1.4 Find the ratio of the perimeter of the square to the circumference of the circle. (Use 22 ) 7 (a) 1:1 (b) 2:1 (c) 11:7 (d) 14:11 1.5 Population of the world is about 6 billion. Population of U.S.A. is about 281,000,000. What percentage of world’s population lives in U.S.A.? (1 billion = 109 ) (a) 28.1 108 6 109 100% 7 (b) 2.81 10 100%6 109 2 . 81 10 8 (c)6 109 100% 9 (d) 6 10 100%281 108 A box contains cookies. w is the weight of the box along with n cookies in it. w, in kg, is given by the formula w = 1.5 + 0.3n. Weight of how many cookies is equal to the weight of the empty box? (a) 4 (b) 5 (c) 6 (d) 7 1.7 Peter is x years old. Peter’s brother is 2 years older than Peter. Peter’s sister is 3 years younger than Peter. Age of Peter’s father is equal to the product of the ages of his three children. What is the age of Peter’s father? (a) x3 x2 6x (b) x3 x2 6x (c) x3 x2 6x (d) x3 x2 6x 1.8 The coordinates of the two opposite corners of a rhombus are (2,3) (2,3) and (5,7). What is the equation of the diagonal that is not passing through these corners? (a) 3x 4y 30 0 (b) 6x 8y 61 0 (c) 2x 3y 15 0 (5,7)(d) 2x 3y 15 0 1.9 Triangle ABC is a right-angled triangle. What is the length of the median AD? A 4 (a) 5 units (b) 6 units (c) 7.5 unitsB D C (d) 13 units 6 What is the perimeter of the shaded square? (a) 6 units 3 (b) 7 units (c) 7.5 units (d) 8.5 units 5 1.11 Which of the following pair of lines have the same x-intercept? (a) 2x 3y 5 0 and 5y 4x 10 0 (b) 2x 3y 3 0 and 4x y 6 0 (c) x y 1 0 and x 3y 1 0 (d) 4x 3y 3 0 and4x y 3 0 1.12 The sum of the interior angles of a polygon is 1080 . How many sides this polygon has? (a) 5 (b) 6 (c) 7 (d) 8 Short-Answer Questions 2.1 John is standing between two walls, wall A and wall B. His distance from wall A is 6 m and from wall B is 5 m. Wall A Wall B John 6 m 5 m John moved towards wall B such that his distance from wall A increased by 8%. What is the percentage decrease in his distance from wall B? Show your work Answer: _____% Equation of a line is Ax By C 0 and A:B:C = 1:2:4. Find the slope, x-intercept and y- intercept of this line. Draw this line on the coordinate plane given below. y 10 9 8 7 6 5 4 3 2 1 x -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 Show your work Answer: Slope = _______, x-intercept = _______, y-intercept = _______ ABCD is a square and points D, E, F, G are the midpoints of its A G D sides. What percentage area of the square is shaded? D F B E C Show your work Answer: ______% 2.4 2000 people lived in a village in the year 1999. By the year 2004, the male population has increased by 10% and the female population has decreased by 6%, but the total population has remained unchanged. How many males were in the village in the year 1999? Show your work Answer: _______ males. Find the volume of a hollow sphere whose outer diameter is 4 cm and thickness is 1 cm. (Use 22 ) 7 Show your work Answer: _______ cubic cm. Tasks 3.1 Station X and station Y are 300 km apart. Car A is at station X and car B is at station Y. Station 300 km Station X Y At time t = 0, car A and car B start moving simultaneously. The movement of the cars is in the following manner: Stage 1: For 1 hr., car A moves towards station Y with speed 100 km per hour and car B moves towards station X with speed 50 km per hour. Stage 2: For the next 1 hr., car A stops and remains stationary but car B keeps moving towards station X with speed 50 km per hour. Stage 3: For the next 1 hr., car A moves towards station Y with speed 100 km per hour but car B stops and remains stationary. Stage 4: For the next 1 hr., car A keeps moving towards station Y with speed 100 km per hour and car B moves towards station X with speed 50 km per hour. (a) Complete the following graph for stages 2, 3 and 4. Graph for stage 1 has been drawn. 300 Car B 250 200 150 100 50 Car A 0 1 2 3 4 Time, t (hr.) Show your work (b) Look at both the graphs and answer the following questions. (i) After what time the cars meet? Answer: _____ hrs. (ii) When car A reaches station Y, how far is car B from station X? Answer: _____ km. (iii) What is the distance between the cars after 1 hr.? Answer: _____ km. (iii) What is the distance between the cars after 2 hr.? Answer: _____ km. Show your work In a triangle ABC, AD BC, BE AC and CF AB.A AD, BE and CF meet at P. ABC = 56 and ACB = 42 . E (a) Write the correct answers. F P (i) BAC = _____ (ii) FPA = _____ (iii) APE = _____ (iv) EPC = _____ B D C (v) CPD = _____ (vi) DPB = _____ (vii) BPF = _____ Show your work (b) To make the following statements true, write one of the triangles ACD, ACF, ABD in the spaces below. (i) FPA is similar to _______ (ii) PEA is similar to _______ (iii) EPC is similar to _______ Show your work Peter has a rectangular piece of paper with corners 5 cm C marked A, B, C, D. Length of the sides of the paper are 3 cm and 5 cm. Peter folded the paper such that the corner D touches side AB as shown in figure.E 3 cm (a) Write the correct answers. (i) Length of side BD = ______ cm (ii) Length of side AD = ______ cm A D B Show your work (b) Are BDC and DAE similar? Yes No Explain your answer. Show your work (c) Write the correct answers. (i) Length of side AE = ______ cm (ii) Length of side DE = ______ cm (iii) Area of DEC = _______ sq. cm (iv) Area of trapezoid ABCE = ______ sq. cm (v) Ratio of area of DEC to area of trapezoid ABCE = _________ Show your work ANSWERS 1.1 The car is moving on the circular path, hence the distance of the car from the center of the circular path is a constant and it does not change with time. Answer: (d) 1.2 Slope of the line = 1 x 1 x 212x 1 x 1 1x 1 x 1 1 x 2 Hence, the points are (2,4) and (5,3) Hence, the equation of the line is y 4 1 x 2 y x 2. Answer: (d) 1.3 Diagonals of a rhombus are perpendicular to each other. Slope of line 3x 4y 5 0 is 3 and slope of line 4x 3y 7 0 is 4 . 4 3 Hence, the product of their slopes is –1. Hence these lines are perpendicular and they can be the diagonals of a rhombus. The other three pair of lines are not perpendicular. Hence, they cannot be the diagonals of a rhombus. Answer: (b) 1.4 Let the diameter of the circle = d Hence, length of the side of the square = d Hence, perimeter of the square = 4d Hence, circumference of the circle = d22d7 Hence, Perimeter : circumference = 4d : 22d = 28 : 22 = 14 : 117 Answer: (d) 1.5 Population of the world = 6 billion = 6 109 Population of U.S.A. = 281,000,000 = 2.81 108 Hence, percentage of world’s population living in U.S.A. = 2.81 108 6 109 100% Answer: (c) 1.6 w = 1.5 + 0.3n Hence, if 1 cookie is added, the weight changes by 0.3 kg Hence, weight of 1 cookie = 0.3 kg When there is no cookie in the box, n = 0, w = 1.5 kg Hence, weight of empty box = 1.5 kg Number of cookies whose weight equals weight of empty box = 1.5 50.3 Answer: (b) 1.7 Age of Peter = x years Age of Peter’s brother = x + 2 years Age of Peter’s sister = x – 3 years Age of Peter’s father = x x 2 x 3 x x2 2x 3x 6 x x2 x 6 x3 x2 6x Answer: (c) 1.8 Slope of the diagonal passing through the given corners = 7 3 4 5 2 3 Diagonal of a rhombus are perpendicular and they bisect each other. Hence, the slope of the other diagonal = 3 4 Hence, midpoint of the diagonals is 2 5,3 7 , which is 7,52 2 2 Hence, equation of the other diagonal is y 5 3x 7 4 2 4 y 20 3 x 21 2 8y 40 6x 21 6x 8y 61 0 Answer: (b) 1.9 D is the mid point of BC Length of BC = 6 units Hence, length of BD = 3 units ABD is right angled triangle Hence, by Pythagorus theorem, AD2 AB2 BD2 AD2 42 32 16 9 25 AD 5 units Answer: (a) 1.10 Let the length of the side of the square = x unitsAHence, BD = DE = x 3-x E AB = 3, hence AD = 3 – x D x DE BC, hence DEA = BCA (corresponding angles) B C ADE = ABC = 90 Hence, ADE and ABC are similar because two angles are equal. AD DEHence, AB BC 3 x x 3 5 15 5x 3x 8x 15 15x 8 Hence, perimeter of the square = 4x 415 7.5 units8 Answer: (c) 1.11 x-intercept of the line Ax By C 0 is C . A x-intercept of the line 2x 3y 5 0 and 5y 4x 10 0 is 5 , hence they have the 2 same x-intercept. Answer: (a) 1.12 Sum of the interior angles of a n-sided polygon = n 2 180 Hence, n 2 180 1080 1080n 2 180 n 2 6 n 8 Answer: (d) 2.1 John’s distance from wall A = 6 m Increase in distance from wall A = 8 612 m 100 25 Hence, decrease in distance from wall B = Increase in distance from wall A = 12 m 25 John’s distance from wall B was = 5 m Hence, percentage decrease in his distance from wall B = 12 1 100 9.6%25 5 Answer: 9.6% 2.2 A:B:C = 1:2:4 Slope = A 1 ; x-intercept = C 4; y-intercept = C 4 2B 2 A B 2 y Answer: Slope = 10 9 8 7 6 5 4 3 2 1 x -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 1 ; x-intercept = 4; y-intercept = 22 2.3 Let the length of the side of the square = 2xA G D D, E, F, G are midpoints of the sides. Hence, AD = AG = CE = CF = xF Hence,D (area of ADG) + (area of CEF)B E C = 1x2 1x2 2 2 = x2 Hence, area of the shaded region = area of square ABCD (area of ADG) (area of CEF) = 2x2 x2 = 3x2 Hence, percentage of shaded area = 3x2 4x2 100 75% Answer: 75% 2.4 Let the number of males in the year 1999 = n Hence, number of females in the year 1999 = 2000 n Male population increased by 10% by the year 2004. Hence, male population in the year 2004 = n10 n110n11n100 100 10 Female population decreased by 6% by the year 2004. Hence, female population in the year 2004 = 2000 n6 2000 n100 2000 n 1206 n100188094 n100 Total population remained unchanged. Hence, 11n 188094 n 200010 100 16 n 120100 n 120100 75016 Answer: 750 males 2.5 Outer diameter of the sphere = 4 cm Hence, outer radius of the sphere = 2 cm Thickness = 1 cm Hence, radius of the spherical hollow region = 2 cm – 1 cm = 1 cm Hence, volume of the hollow sphere = Volume of the outer spherical region – Volume of the spherical hollow region = 4 23 4 13 cubic cm 3 3 =4 22 84 22 cubic cm 3 7 3 7 4 22 7 cubic cm3 7 =88 cubic cm 3 =291 cubic cm 3 Answer: 291 cubic cm 3 3.1 (a) During stage 2, car A remains stationary. Hence, distance of the car A from station X is a constant and so its graph must be a horizontal line. Car B moves towards station X with speed 50 km per hour, hence during one hour, distance of car B from station X decreases by 50 km. During stage 3, car A moves towards station Y with speed 100 km per hour, hence during one hour, distance of car A from station X increases by 100 km. Car B remains stationary, hence distance of car B from station X remains constant. During stage 4, car A moves towards station Y with speed 100 km per hour, hence during one hour, distance of car A from station X increases by 100 km. Car B moves towards station X with speed 50 km per hour, hence during one hour distance of car B from station X decreases by 50 km. 300 Car B 250 200 150 100 50 Car A 0 1 2 3 4 Time, t (hr.) 3.1 (b) (i) Answer: 3 hrs. (ii) Answer: 150 km. (iii) Answer: 150 km. (iv) Answer: 100 km. 3.2 (a) (i). A BAC = 180 ABC ACB = 180 56 42 = 82E (ii).F P ABD is a right angled triangle Hence, BAD = 90 ABD = 90 56 = 34 AFP is a right angled triangleB D C Hence, FPA = 90 FAP = 90 34 = 56 (iii). ADC is a right angled triangle Hence, DAC = 90 ACD = 90 42 = 48 AEP is a right angled triangle Hence, APE = 90 EAP = 90 48 = 42 (iv). AFC is a right angled triangle Hence, ACF = 90 FAC = 90 82 = 8 CEP is a right angled triangle Hence, EPC = 90 ECP = 90 8 = 82 (v). CPD = FPA = 56 (They are vertical angles) (vi). DPB = APE = 42 (They are vertical angles) (vii). BPF = EPC = 82 (They are vertical angles) 3.2 (b) (i) FPA is similar to ABD because both are right angled triangle and FAP is common to both (ii) PEA is similar to ACD because both are right angled triangle and EAP is common to both (iii) EPC is similar to ACF because both are right angled triangle and ECP is common to both 3.3 (a) (i) DBC is a right angled triangle, BC = 3 cm, CD = 5 cm Hence, by Pythagorus theorem BD2 CD2 BC2 52 32 25 4 16 So, BD = 4 cm (ii) AD = AB – BD = 5 cm – 4 cm = 1 cm 3.3 (b) AED and BDC are complimentary angles of ADE hence they are equal. Hence BDC and DAE are similar because both are right angle triangle and one of their other angle are equal. 3.3 (c) (i) BDC and DAE are similar hence AE BD AE4 14 cm AD BC 3 3 (ii) BDC and DAE are similar hence DE CD DE5 15 cm AD BC 3 3 (iii) Area of DEC = 1 DE CD1 5 525 sq. cm2 2 3 6 (iv) Area of trapezoid ABCE =1 AE BC AB1 4 3 51 13 585 sq. 2 2 3 2 3 6 cm (v) Ratio of area of DEC to area of trapezoid ABCE =25:85 5:136 6 THIS PAGE IS INTENTIONALLY LEFT BLANK GRADE 9 ASSESSMENT OF MATHEMATICS Multiple-Choice Questions: Question no. 1.1 to 1.12 Short-Answer Questions: Question no. 2.1 to 2.5 Tasks: Question no. 3.1 to 3.3 Test Paper No. 2 PREPARED BY: Sanjiva Dayal (sanjivadayal@yahoo.com) Multiple-Choice Questions 1.1 A cone of height 4.5 cm is melted and formed into a sphere of diameter 9 cm. What is the radius of the cone? (a) 9 cm (b) 10 cm (c) 11 cm (d) 12 cm 1.2 $1000 is to be divided among Tom, Jack, Mary and Kate. 30% of the money was given to Tom, 30% of the balance amount was given to Jack, 30% of the balance amount was given to Mary. The remaining amount of money was given to Kate. Who received the largest amount of money? (a) Tom (b) Jack (c) Mary (d) Kate 1.3 Two sides of the right-angled triangle are x y 1 0 and 2x 4y 7 0. Which of the following line cannot be the third side of the triangle? (a) x y 2 0 (b) 2x 2y 7 0 (c) 2x y 1 0 (d) 2x 3y 7 0 1.4 Two trains are 1000 km apart. They start moving towards each other. One train is moving with a speed of 110 km per hour and the other train with a speed of 90 km per hour. The distance between the trains after time t is d. What is the formula of d, in km, as a function of time t, in hr? (a) d = 1000 – 20t (b) d = 1000 + 20t (c) d = 1000 – 200t (d) d = 1000 + 200t Which of the following line does not have x-intercept? (a) y x (b) y x (c) y 3 (d) x 4 1.6 A hollow cylindrical vessel has radius 3 inches and height 8 inches. What is the greatest length of the stick that can be kept inside the vessel? (Stick should not be bent or broken and no part of the stick should be outside the vessel) (a) 6 inch (b) 8 inch (c) 10 inch (d) 12 inch 1.7 Length of bacteria is about 0.000003 inch. How many bacteria would fit in 1 mm length? (1 inch = 2.54 cm) 2.54(a) 3 107 10 (b) 10 3 106 2.54 (c) 2.54 10 3 106 1(d) 3 106 2.54 10 1.8 Lines 2x 3y 7 0 and x y 3 0 are the diameter of a circle. Which of the following point is the center of the circle? (a) (1,2) (b) (3,2) (c) (2,1) (d) (2,3) The length, width and height of a rectangular prism are x y units, 2x y units and x 2y units respectively. What is the surface area of the rectangular prism? (a) 8x2 20xy 8y2 sq. units (b) 10x2 22xy 10y2 sq. units (c) 4x2 10xy 4y2 sq. units (d) 5x2 11xy 5y2 sq. units 1.10 Peter scored 20% marks in an examination and he failed by 30 marks. Mary scored 30% marks in the same examination and she failed by 10 marks. What is the passing percentage of marks in the examination? (a) 35% (b) 40% (c) 45% (d) 50% 1.11 The angles of a hexagon are x , x 10 , x 20 , x 30 , x 40 and x 50 . What is x? (a) 75 (b) 85 (c) 95 (d) 105 1.12 ABC is an isosceles triangle. AB = AC, EF BC and EAC = 128 . What is BAC? E A F (a) 52 (b) 54 (c) 66 (d) 76 B C Short-Answer Questions 2.1 The height of a tree, h, and the diameter of the tree, d, are tabulated below at different time, t. t (years) 1 3 4 7 h (ft) 3 4 5 6 d (inch) 2 4 5 8 Plot these values in the graphs given below and check whether h and d are linear functions or non- linear functions of time. 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 0 1 2 3 4 5 6 7 t (years) 0 1 2 3 4 5 6 7 t (years) Show your work Answer: h is a Linear function d is a Linear function Non-linear function Non-linear function The vertices A, B, C of a triangle are (3, 1), (2,3) and A (1,1) respectively. What is the equation of the median AD? B D C Show your work Answer: Equation of the median AD is __________________ 2.3 Peter has a rectangular piece of board. He cut out a circular disk and a semicircular disk from the board. What percentage area of the board is left with him? (Use 3.14. Round off your answer to the nearest tenth) Show your work Answer: ______ % The midpoints of the sides of a triangle are (1,4), (4,8) andA (5,6). What is the equation of the side BC? (1,4) (5,6) B (4,8) C Show your work Answer: Equations of the side BC is ________________________ Figure ABCD is a square having side length a. Figure CEFG is a A a D rectangle having width b. Figure DBF is a straight line. Perimeter of the square ABCD is equal to the perimeter of the rectangle CEFG. What is the ratio a:b? E B C b F G Show your work Answer: a:b = _______ Tasks 3.1 When wheels of a car make one revolution, the distance moved by the car is equal to the circumference of the wheel. d d When the diameter of the wheels is d, in meters; and the wheels are rotating at the rate of n revolutions per second, the velocity of the car v, in meters per second, is given by the formula v dn (Use 22 ).7 (a) Diameter of the wheels of a car is 70 cm. (i) Express v as a function of n. Answer: ________ (ii) What is the speed of the car when the wheels are rotating at the rate of 5 revolutions per second? Answer: _______ meters per second. Show your work (b) Due to the leakage of air, the diameter of the wheels decreases by 50%. (i) Expressv as a function of n after leakage of air. Answer: ____________ (ii) What should be the rate of rotation of wheels after leakage of air in order to maintain the same speed as before? Answer: _______ revolutions per second. (iii) What is the percentage increase in the rate of rotation of wheels? Answer: ____ % Show your work (c) Draw graphs of v versus n before the leakage of air and after the leakage of air. 12 10 8 6 4 2 0 1 2 3 4 5 6 7 8 9 10 11 n (revolutions per second) Show your work There are two rectangular sheet of paper of same size, each measuring 22 cm in length and 11 cm in width. A cylinder A was made by rolling one sheet of paper along its length and another cylinder B was made by rolling the other sheet of paper along its width. (Use 22 ) 7 11 cm 22 cmPaper Paper 22 cm11 cm Cylinder A Cylinder B (a) The radius of Cylinder A = _____ cm Show your work (b) Volume of Cylinder A = _____ cubic cm Show your work (c) The radius of Cylinder B = _____ cm Show your work (d) Volume of Cylinder B = _____ cubic cm Show your work (e) Ratio of volume of Cylinder A to volume of Cylinder B = _______ Show your work In the ABC, ACB=78 . AP is the angular bisector ofC CAB. BP is the angular bisector of CBA. 78 P Answer the following questions. A B (a) Is APB = 180 ( PAB + PBA)? Yes No Show your work (b) Is APB = 1801 CAB CBA ? Yes No2 Show your work (c) Is APB = 901 ACB? Yes No2 Show your work (d) APB = _____ degrees. Show your work ANSWERS 1.1 Let the radius of the cone = x cm Given; height of the cone = 4.5 cm Hence, volume of the cone = 1 x2 4.5 cubic cm3 Given; diameter of sphere = 9 cm, hence radius = 4.5 cm Hence, volume of the sphere = 4 4.53 cubic cm3 Both the volumes should be equal 1 x2 4.54 4.53 3 3 x2 4 4.52 x 9 cm Answer: (a) 1.2 30% of $1000 was given to Tom Hence, money received by Tom = 30 $1000 = $300 100 Hence, balance amount = $1000 $300 = $700 30% of balance amount was given to Jack Hence, money received by Jack = 30 $700 $210100 Hence, balance amount = $700 $210 = $490 30% of balance amount was given to Mary Hence, money received by Mary = 30 $490 $147100 Hence, remaining amount received by Kate = $490 $147 = $343 Hence, Kate received the largest amount of money Answer: (d) 1.3 Slope of the line x y 1 0 is 1 Slope of the line 2 x 4 y 7 0 is 1 2 These two given sides are not perpendicular, hence the third side must be perpendicular to one of these sides Slope of the line 2x 3y 7 0 is 2 and so this line is not perpendicular to any of3 the given sides and so it cannot be the third side. The other three lines are perpendicular to one of the given sides and they can be the third side. Answer: (d) 1.4 Trains are moving towards each other at speeds 110 km per hour and 90 km per hour. Hence, the distance between them is decreasing at the rate of 110 + 90 = 200 km per hour. Initially the distance between them is 1000 km. Hence, d = 1000 – 200t Answer: (c) 1.5 Line y = 3 is parallel to x-axis and so it does not have x-intercept. Answer: (c) 1.6 The position of the largest stick is as shown in the figure Diameter of the cylindrical vessel = 2 3 = 6 inches Let the length of the stick = l8 Hence, by Pythagorus theorem l2 62 82 36 64 1006 l 10 inches Answer: (c) 1.7 Length of bacteria = 0.000003 inch = 3 106 inch = 3 106 2.54 10 mm 1Hence, number of bacteria in 1 mm = 3 10 6 2.54 10 Answer: (d) 1.8 Diameters of a circles meet at the center Hence, the center of the circle is the point which lies on both the diameters Point (2,1) lies on the diameter 2x 2 2 3 1 7 0 Point (2,1) lies on the diameter x 3y 7 0 because y 3 0 because 2 1 3 0 The other three points do not lie on both the diameters Hence, center of the circle is (2,1) Answer: (c) 1.9 Surface area of the prism 2 l b l h b h 2 x y 2x y x y x 2y 2x y x 2y 2 2x2 xy 2xy y2 x2 2xy xy 2y2 2x2 4xy xy 2y2 2 5x2 11xy 5y2 10x2 22xy 10y2 Answer: (b) 1.10 Let the maximum marks in the examination = x Peter scored 20% marks Hence, Peter scored = 20 x marks 100 Peter failed by 30 marks Hence, passing marks = 20 x 30 marks100 Mary scored 30% marks Hence, Mary scored = 30 x marks100 Mary failed by 10 marks Hence, passing marks = 30 x 10 marks100 Hence, 20 x 30 30 x 10100 100 10 x 20100 x 200 Hence, passing marks = 30 200 10 60 10 70 marks100 Hence, percentage passing marks = 70 100 35%200 Answer: (a) 1.11 Sum of the angles of n-sided polygon = (n – 2) 180 Hence, sum of the angles of a hexagon = (6 – 2) 180 = 720 Hence, x x 10 x 20 x 30 x 40 x 50 720 6x 150 720 6x 570 x 95 Answer: (c) 1.12 FAC = 180 EAC = 180 128 = 52E A F (Supplementary angles) BCA = FAC = 52 (Alternate angles) CBA = BCA = 52 (Equal angles of isosceles triangle) BAC = 180 CBA BCA B C = 180 52 52 = 76 Answer: (d) 2.1 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 t (years) t (years) Graph of h versus t is non-linear but graph of d versus t is linear. Answer: h is a non-linear function of t. d is a linear function of t. 2.2 D is the midpoint of BC Coordinates of B and C are (2,3) and (1,1) respectively Hence, coordinates of D are 2 1,3 1 , which is 3,22 2 2 Coordinates of A are (3, 1) Hence, slope of AD = 2 1 3 2 6 23 3 3 6 3 2 Hence, equation of AD is y 1 2 x 3 or y 1 2x 6 or 2x y 5 0 Answer: Equation of the median AD is 2x y 5 0. 2.3 Let the radius of the disks = r Hence, area of the circular disk = r2 Hence, area of the semicircular disk = 1r2 2 Length of the rectangle = 3 r Width of the rectangle = 2r Area of the rectangle = 3r 2r 6r2 Area of the board left = 6 r 2 r2 1 r2 6r2 3 r2 2 2 6r2 3 r2 63 3.14 Percentage area of the board left = 2 6r2 100%2 100% 21.5%6 Answer: 21.5% 2.4 Line joining midpoints of the two sides of a triangle is parallel to the third side. 6 4 1Slope of the line joining points (1,4) and (5,6) = 5 1 2 1Hence, slope of BC = 2 BC passes through the point (4,8) Hence, equation of BC is y 81 x 4 or 2y 16 x 4 or x 2y 12 02 Answer: Equation of the side BC is x 2y 12 0 . 2.5 ADB = 45 (Angle between diagonal and side of a square)A a D AD EC, hence, EBF = ADB = 45 FEB = 90 , hence EFB = 180 90 45 = 45 = EBF Hence, BE = EF = b E B C Hence, length of the rectangle = EC = BE + BC = b + ab F G Hence, perimeter of rectangle = 2(a + b + b) = 2a + 4b Hence, perimeter of the square = 4a Perimeter of square and rectangle are equal 2a + 4b = 4a 2a = 4b a = 2b Hence, a: b = 2:1 Answer: 2:1 3.1 (a) (i) Diameter of the wheel = d = 70 cm = 0.7 m Hence, v22 0.7 n 2.2n7 v 2.2n (ii) Given; n = 5 revolutions per second Hence, v 2.2 5 11 meters per second v 11 meters per second 3.1 (b) (i) Diameter of the wheel decreases by 50% Hence, after leakage, d = 50 0.7 0.35 cm 100 Hence, v22 0.35 n 1.1n7 v 1.1n (After leakage of air) (ii) Speed after leakage is same as before, which is 11 meters per second Hence, 11 1.1n n11 10 revolutions per second 1.1 n 10 revolutions per second (iii) Rate of rotation has increased from 5 revolutions per second to 10 revolutions per second Hence, percentage increase in the rate of rotation of wheels =10 5 100% 100%5 Percentage increase in the rate of rotation of wheels = 100% 3.1 (c) v 2.2n (Before leakage of air) v 1.1n (After leakage of air) 12 10 Before 8 leakage Afterof air leakage of 6 air 4 2 0 1 2 3 4 5 6 7 8 9 10 11 n (revolutions per second) 3.2 (a) Let the radius of Cylinder A = r cm Length of the paper = circumference of the Cylinder A = 22 cm Hence, 2 r 22 222 r 227 r 227 1 cm 22 2 r 3.5 cm Answer: The radius of Cylinder A = 3.5 cm 3.2 (b) Width of the paper = height of the Cylinder A = 11 cm Hence, volume of Cylinder A = r 2 height22 3.52 1122 7 2 7 7 2 11 423.5 cubic cm Answer: Volume of Cylinder A = 423.5 cubic cm 3.2 (c) Let the radius of Cylinder B = R cm Width of the paper = circumference of the Cylinder B = 11 cm Hence, 2 R 11 222 R 117 R 117 1 cm 22 2 R 1.75 cm Answer: The radius of Cylinder B = 1.75 cm 3.2 (d) Length of the paper = height of the Cylinder B = 22 cm Hence, volume of Cylinder B 22 1 . 75 2 22 227 2 = R2 height7 7 4 22 211.75 cubic cm Answer: Volume of Cylinder B = 211.75 cubic cm 3.2 (e) Ratio of volume of Cylinder A to volume of Cylinder B = 423.5:211.75 = 2:1 Answer: Ratio of volume of Cylinder A to volume of Cylinder B = 2:1 3.3 C 78 P A B (a) APB + PAB + PBA = 180 (Angles of a triangle) Hence, APB = 180 ( PAB + PBA) Answer: Yes 3.3 (b) PAB = 1 CAB (AP is angular bisector of CAB) 2 PBA = 1 CBA (BP is angular bisector of CBA) 2 Hence, APB = 180 ( PAB + PBA) = 1801 CAB CBA2 Answer: Yes 3.3 (c) CAB + CBA + ACB = 180 (Angles of a triangle) APB = 1801 CAB CBA2 = 1801 180 ACB2 = 180 901 ACB2 = 901 ACB2 Answer: Yes 3.3 (d) APB = 901 ACB 901 78 90 39 1292 2 Answer: 129 THIS PAGE IS INTENTIONALLY LEFT BLANK GRADE 9 ASSESSMENT OF MATHEMATICS Multiple-Choice Questions: Question no. 1.1 to 1.12 Short-Answer Questions: Question no. 2.1 to 2.5 Tasks: Question no. 3.1 to 3.3 Test Paper No. 3 PREPARED BY: Sanjiva Dayal (sanjivadayal@yahoo.com) Multiple-Choice Questions 1.1 Peter has 50 coins. n coins are nickel and the rest are dimes. Q, in dollars, is the total amount of money with Peter. What is the formula of Q? (a) Q = 5 – 0.05 n (b) Q = 50 – (c) Q = 500 – (d) Q = 50 – 0.1n 1.2 Which of the following geometrical objects has same number of triangular faces as square pyramid? (a) Triangular prism (b) Triangular pyramid (c) Cone (d) Hexagonal pyramid 1.3 Speed of light is 300,000,000 meter per second. Distance of Sun from Earth is 150,000,000 km. How many minutes light takes to reach Earth from Sun? (a) 1.5 108 1000 minutes3 108 60 (b) 15 108 1000 minutes3 108 60 (c) 1.5 108 3 108 60 minutes 15 10 8 (d) 1000 minutes3 108 1.4 Vertices A, B, C of a triangle are (2,1), (3,2) and A (5, 4) respectively. What is the equation of the line which passes through A and is perpendicular to the median AD? (a) x y 1 0 (b) x y 1 0B D C (c) x y 1 0 (d) x y 1 0 A car is moving on a road with constant speed. A building is situated away from the road. d is the distance of the car from the building. Building d Car Road Which of the following graphs show the relationship between d versus time? (a) d time d (b) time (c)d time (d) d time 1.6 Cost price of 10 toys is equal to the selling price of 16 toys. What is the profit or loss percentage? (a) 28% profit (b) 37.5 % profit (c) 28% loss (d) 37.5% loss a3b2c6 4 balls are distributed equally among a2b5c4 2 boys. How many balls each boy has? (a) a6c16 b2 a 8c16 (b) b2 8c14 (c) a b2 a 6 c14 (d) b 1.8 Which of the angle is three times of its complementary angle? (a) 135 (b) 67.5 (c) 50.5 (d) 45 1.9 Surface area of the square based pyramid is 75 sq. cm. What is the area of each triangular face? (a) 18.75 sq. cm (b) 25 sq. cm (c) 12.5 sq. cm (d) 15 sq. cm 5 cm 1.10 A point A is in second quadrant and a point B is in fourth quadrant. Which of the following statement is always true? (a) Line joining A and B has negative slope (b) Line joining A and B has positive slope (c) Line joining A and B has slope greater than 1 (d) Line joining A and B has slope between 0 and 1 A line is drawn through the points (x,1) and (3,2). The slope of this line is 1 . What is x? x (a) 1 (b) 3 2 (c) 2 (d) 3 1.12 Which of the following statement is always true? (a) Similar triangles are congruent (b) Congruent triangles are similar (c) Similar triangles are equal in area (d) Similar triangles are equal in perimeter Short-Answer Questions 2.1 Draw the lines y x 2 and y 2x 3 on the coordinate plane given below and find the coordinates of their point of intersection. y 10 9 8 7 6 5 4 3 2 1 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10x -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 Show your work Answer: Coordinates of point of intersection is _______. Find the number x such that the area of the figure given below is 50 sq. units. 6 x 4 12 Show your work Answer: x = _____ units. The ratio of number of boys to girls is 2:3. Number of girls increased from 12 to 16. What is the ratio of boys to girls now? Show your work Answer: _____. 2.4 The average age of 5 children in a family is 9 years. The average age of these 5 children together with their parents is 20 years. The father is 5 years older than the mother. What is the age of the father? Show your work Answer: Age of the father is _____ years. What is the ratio of the total area of the three circles to the A D area of the rectangle ABCD? B C Show your work Answer: Ratio is _______ Tasks 3.1 A tank contains 180 liters of alcohol. Everyday 60 liters of liquid is taken out of the tank and 60 liters of water is put in it. (a) Calculate the quantity of alcohol remaining in the tank after 1 day, 2 days and 3 days and complete the table given below. (Round off your answer to the nearest tenth) Days 0 1 2 3 Quantity of alcohol 180in the tank (liters) Show your work (b) Complete the graph of quantity of alcohol in the tank versus days. 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 01 23 Days (c) Look at the graph and check whether the quantity of alcohol as a function of days is a linear function or a non-linear function. Explain your answer. Linear function Non-linear function Explain your answer 3.2 A metal cylinder has height 12 cm and diameter 10 cm. A conical hole is drilled in this metal cylinder. The height and 10 radius of conical hole is same as that of the cylinder. The solid remaining after drilling the conical hole is shown in the figure. (Use = 3.14) 12 (a) What is the volume of the conical hole? Answer: ______ cubic cm Show your work (b) What is the volume of the remaining solid? Answer: ______ cubic cm Show your work (c) What is the slant height of the conical hole? Answer: ______ cm Show your work (d) What is the surface area of the remaining solid? Answer: ______ sq. cm Show your work 3.3 A circle is drawn with center O. A point P is taken on its Q circumference. From the point P, two chords PQ and PR are drawn. Lengths of PQ and PR are equal to the radius of the circle. P O (a) QPR = ______ R Show your work (b) PQO = ______ Show your work (c) PRO = ______ Show your work (d) QOR = ______ Show your work (e) Is figure PQOR a rhombus? Yes No Show your work ANSWERS 1.1 Peter has 50 coins out of which n coins are nickel. Hence, number of coins which are dimes = 50 – n Value of n nickel coins = $0.05n Value of (50 – n) dimes = $(50 – n) 0.10 = $(5 – 0.1n) Total value of coins = $(0.05n + 5 – 0.1n) = $(5 – 0.05n) Hence, Q = 5 – 0.05n Answer: (a) 1.2 Square pyramid and triangular pyramid both have 4 triangular faces Answer: (b) 1.3 Speed = 300,000,000 meters per second= 3 108 meters per second Distance = 150,000,000 km = 1.5 108 km = 1.5 108 1000 meters Distance 1 . 5 10 8 1000 seconds = 1.5 108 Time =1000 minutesspeed 3 108 3 108 60 Answer: (a) 1.4 D is the midpoint of BC. Hence, coordinates of D are 3 5,2 4 or (4, 1)2 2 Coordinates of A are (2,1) Hence, slope of AD =1 1 2 14 2 2 Hence, slope of line which is perpendicular to AD is 1 Hence, equation of line which is perpendicular to AD and passes through A is y 1 1 x 2 or x y 1 0 Answer: (d) 1.5 As the car moves along the road, its distance decreases with time and then it increases with time. The least distance between the car and the building is the distance between the building and the road. Answer: (d) 1.6 Let the cost price of 1 toy = $ x Hence, cost price of 10 toys = $10x Hence, selling price of 16 toys = cost price of 10 toys = $10x 10x $5xHence, selling price of 1 toy = $16 8 5x x, hence selling price is less than cost price8 x 5 Hence, loss percentage = 8 x 3 100% 37.5%x 100%8 Answer: (d) 1.7 Number of balls with each boy = a3b2 c64 a3 4b2 4c6 4 a12b8c24 a12 4c24 8 a8c16 2a2 2b5 2c4 2a4b10c8b10 8b2a2b5c4 Answer: (b) 1.8 Let the angle = x Hence, complementary angle = 90 x Angle is three times its complementary angle Hence, x = 3(90 x) x = 270 3x 4x = 270 x = 270 67.53 Answer: (b) 1.9 Base is square of side length = 5 cmHence, area of base = 5 5 sq. cm = 25 sq. cm Pyramid has 4 triangular faces. Hence, Surface area of the pyramid = Area of square base + Area of four triangular faces Hence, Area of four triangular faces = 75 sq cm – 25 sq. cm = 50 sq. cm Hence, area of each triangular face = 50 12.5 sq. cm4 Answer: (c) 1.10 Line joining point A and B will be always slant downward from left to right, hence slope is always negative. Answer: (a) 1.11 Slope of the line joining the two given points = 2 1 1 3 x 3 x 1The slope is given to be x 1 1Hence, 3 x x x 3 x 2x 3 3x 2 Answer: (b) 1.12 Congruent triangles are similar because their angles are equal. Answer: (b) 2.1 Line y x 2 has slope 1 and y-intercept 2 Line y 2x 3 has slope 2 and y-intercept 3 y 10 9 8 7 6 5 4 3 2 1 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10x -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 Answer: Coordinates of point of intersection is (5,7). 2.2 Draw a rectangle with dotted lines as shown in the figure2 One side of the rectangle with dotted sides is6 x 6 – 4 = 2 units and the other side is x units4 The area of the given figure = (Area of rectangle of sides 12 units and 6 12 units) (Area of rectangle of sides 2 units and x units) = 12 6 – 2 x = 72 – 2x Area given is 50 sq. units Hence, 72 – 2x = 50 2x = 72 – 50 2x = 22 x = 11 units Answer: x = 11 units. 2.3 Ratio of boys to girls = 2:3 Number of girls = 12 Hence, number of boys = 2 12 83 Now, number of girls increased to 16 Hence, ratio of boys to girls = 8:16 = 1:2 Answer: 1:2 2.4 Let the age of father = x years Hence, age of mother = x – 5 years Average age of 5 children = 9 years Hence, total age of children = 9 5 = 45 years Hence, average age of children together with their parents = 45 x x 5 40 2x 7 7 years But average age of the family is 20 years (Given) Hence, 40 2x 207 40 2x 140 2x 100 x 50 Answer: Age of the father is 50 years. 2.5 Let the diameter of the two small spheres = x units A D Hence, diameter of the large sphere = 2x unitsx Hence, radius of the large sphere = x units2x Hence, sides of the rectangle are 2x units and 3x units Hence, the total area of the three circlesB C = x 2 x2 x2 3 x2 4 4 2 sq. units Hence, the area of the rectangle = 2x 3x 6x2 sq. units Hence, ratio of the total area of three circles to the area of rectangle is 3 x2 2 :6x2 or : 4 Answer: Ratio is : 4. 3.1 (a) After first day 60 liters of liquid taken out is alcohol Hence, amount of alcohol in the tank = 180 – 60 = 120 liters 60 liters of water is added Hence, fraction of alcohol in the liquid = 120 2 180 3 After second day 60 liters of liquid taken out is 2 alcohol 3 Hence, quantity of alcohol taken out = 2 60 40 liters 3 Hence, quantity of alcohol in the tank = 120 – 40 = 80 liters 60 liters of water is added Hence, fraction of alcohol in the liquid = 80 4 180 9 After third day 60 liters of liquid taken out is 4 alcohol 9 Hence, quantity of alcohol taken out =4 60 26.7 liters 9 Hence, quantity of alcohol in the tank = 80 – 26.7 = 53.3 liters Days 0 1 2 3 Quantity of alcohol 180 120 80 53.3in the tank (liters) 3.1 (b) 180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0 01 23 Days 3.1 (c) The points on the graph does not lie on a straight line. Hence, quantity of alcohol as a function of days is a non-linear function. 3.2 (a) Radius of the conical hole = 5 cm Height of the conical hole = 12 cm 10 Hence, volume of the conical hole = 1 r2h1 3.14 52 12 314 cubic cm 3 3 12 Answer: 314 cubic cm 3.2 (b) Volume of the cylinder before drilling the hole = r2h 3.14 52 12 942 cubic cm Hence, volume of the remaining solid = 942 – 314 = 628 cubic cm Answer: 628 cubic cm 3.2 (c) Let slant height of the conical hole = l cm By Pythagorus theorem, l2 122 52 144 25 169 132 Hence, l 13 Answer: 13 cm 3.2 (d) Surface area of the remaining solid = Area of the outer cylindrical curved surface + Area of the base + Area of the inner conical curved surface = 2 rh r2 rl = 2 3.14 5 12 3.14 52 3.14 5 13 = 376.8 + 78.5 + 204.1 sq. cm = 659.4 sq. cm Answer: 659.4 sq. cm 3.3 (a) Join the center O to the point P PQ = PO = OQ = PR = OR (Their lengths are equal to theQ radius of the circle) Hence, POQ and POR are equilateral triangles as their P O sides are equal and all their angles are 60 Hence, QPR = QPO + OPR = 60 + 60 = 120R Answer: QPR = 120 3.3 (b) PQO = 60 (Angle of an equilateral triangle) 3.3 (c) PRO = 60 (Angle of an equilateral triangle) 3.3 (d) QOR = QOP + POR = 60 +60 = 120 Answer: QOR = 120 3.3 (e) All the sides of the figure PQOR are equal to the radius of the circle, hence all the four sides are equal; hence figure PQOR is a rhombus. Answer: Yes THIS PAGE IS INTENTIONALLY LEFT BLANK GRADE 9 ASSESSMENT OF MATHEMATICS Multiple-Choice Questions: Question no. 1.1 to 1.12 Short-Answer Questions: Question no. 2.1 to 2.5 Tasks: Question no. 3.1 to 3.3 Test Paper No. 4 PREPARED BY: Sanjiva Dayal (sanjivadayal@yahoo.com) Multiple-Choice Questions 1.1 In an examination, Peter, Mary and John got 40%, 50% and 60% of the maximum marks respectively. They got 450 marks together. What is the maximum marks? (a) 250 (b) 300 (c) 350 (d) 400 1.2 In ABC, what is DPE? A E P (a) 144 (b) 138 (c) 102 (d) 100 36 42 B D C 1.3 Mean weight of a group of n persons is 40 kg. One person, having weight w, in kg, is included in the group. The mean weight of the group is now 41 kg. What is w in terms of n? (a) w = 40n – 41 (b) w = 40n + 41 (c) w = n + 41 (d) w = n + 81 1.4 Area of Canada is about 9,970,000 sq. km and population of Canada is about 31,900,000. What is the number of persons per sq. km? (a) 319 107 9.97 106 3 . 19 10 7 (b) 99.7 106 3 . 19 10 7 (c) 9.97 106 9 . 97 10 6 (d) 3.19 107 What is the area of the shaded figure? 13 (a) 12 sq. units3 4 (b) 24 sq. units (c) 36 sq. units (d) 48 sq. units 1.6 There are (2x – 1) barrels of oil. Each barrel contains (x + 1) liters of oil. Cost of oil is $( x + 2) per liter. What is the total cost of oil in all the barrels? (a) $ 2x3 5x2 x 2 (b) $ 2x3 7x2 x 2 (c) $ 2x3 5x2 x 2 (d) $ 2x3 5x2 3x 2 1.7 A line passes through the points (a,2) and (3,1). y-intercept of this line is 1. What is the slope of this line? (a) 1 3 (b) 1 3 (c) 2 3 (d) 2 3 1.8 Twelve iron balls, each of diameter 7 cm, are melted and formed in the shape of a cylinder of radius 7 cm. What is the height of the iron cylinder? (a) 14 cm (b) 56 cm (c) 72 cm (d) 112 cm Peter, Mary, Tom and Kate go for a walk. The distances traveled by them are shown on the graph. Peter Mary Tom Kate time Who has the highest average speed? (a) Peter (b) Mary (c) Tom (d) Kate 1.10 An elevator has the capacity of 12 adults or 20 children. How many adults can board the elevator with 15 children? (a) 3 (b) 4 (c) 5 (d) 6 1.11 One of the diagonals of a rhombus is equal to its side. What are the angles of the rhombus? (a) 70 and 110 (b) 60 and 120 (c) 80 and 100 (d) 50 and 130 During a war, 1 of a platoon of solders were killed, 1 died of disease and 1 were taken 5 3 25 prisoners. What fraction of the platoon is left? (a) 29 75 (b) 2 5 (c) 32 75 (d) 7 15 Short-Answer Questions 2.1 Draw the line 2x y 1 0. This line cuts the circle that is drawn on the graph. What are the coordinates of the points of intersections of this line and the circle? y 10 9 8 7 6 5 4 3 2 1 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10x -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 Show your work Answer: Coordinates of the points of intersections are _______ and ________. Peter purchases toys at the rate of 11 toys for $10 and sells the toys at the rate of 10 toys for $11. What is his percentage profit? Show your work Answer: _____ % 2.3 A racing track is shown below. What is the length of the racing track in km? (Use 22 ) 7 84 m 200 m Show your work Answer: ____ km. A pizza shop sells large and small pizzas. 30% of the pizzas are large and the remaining pizzas are small. A Large pizza is sold for $5 and a small pizza is sold for $4. Totalsale on a particular day was $817. How many pizzas were sold on that particular day? Show your work Answer: _____ pizzas. 2.5 An insect is at one corner of the floor of the room. A lizard is at the midpoint of one of the edge of the roof. What is the distance between the insect and the lizard? Lizard 12 m Insect 6 m 4 m Show your work Answer: _____ meters Tasks 3.1 Peter wants to visit his friend who lives 160 km away. Peter noticed that the fuel tank of his car has a hole and fuel is leaking at the rate of I liter per hour. Peter knows that if he drives his car at the speed of 50 km per hour then the fuel consumption rate of his car is 10 km per liter of fuel, but if he drives his car at the speed of 100 km per hour then the fuel consumption rate of his car is 8 km per liter of fuel. At the start of his journey, there is 20 liters of fuel in the tank of his car. Peter wants to know how he can reach his friends house with the leaking fuel tank? (a) What is the distance traveled by Peter till his fuel tank is empty if he drives at the speed of 100 km per hour? (Round off your answer to the nearest hundredth) Answer: ________ km Show your work (b) What is the distance traveled by Peter till his fuel tank is empty if he drives at the speed of 50 km per hour? (Round off your answer to the nearest hundredth) Answer: ________ km Show your work (c) At what speed should Peter drive his car so that he reaches his friends house that is 160 km away? Answer: ____ km per hour Show your work A building is in the shape of a triangular prism. 120 ft 90 ft 100 ft (a) What is the volume of the building? Answer: _________ cubic feet 150 ft Show your work (c) What is the area of the floor? Answer: _________ sq feet Show your work (c) What is the surface area of walls excluding the floor? Answer: _________ sq feet Show your work Figure ABCD is a trapezoid. Its sides D C CD and CB are equal in length. 126 Write the correct answers. (a) CBD = ______ A B Show your work (b) DBA = ______ Show your work (c) DAB = ______ Show your work ANSWERS 1.1 40 50 60 of maximum marks = 450 100 100 100 150 of maximum marks = 450 100 Maximum marks = 100 450 300150 Answer: (b) 1.2 Figure BDPE is a quadrilateral and so sum of its internal angles is 360 Hence, EBD + BDP + DPE + PEB = 360 36 + 90 + DPE + 90 = 360 DPE = 360 36 90 90 = 144 Answer: (a) 1.3 Mean weight of a group of n persons is 40 kg Hence, total weight of n persons = 40n Total weight of the group including the person having weight w kg = 40n + w Hence, the mean weight = 40n w n 1 Mean weight is given to be 41 kg Hence, 40n w 41n 1 40 n w 41 n 1 40n w 41n 41 w 41n 41 40n w n 41 Answer: (c) 1.4 Area of Canada = 9,970,000 sq. km = 9.97 106 sq. km Population of Canada = 31,900,000 = 3.19 107 persons Hence, number of persons per sq. km = 3.19 107 9.97 106 persons per square km Answer: (c) 1.5 By Pythagorus theorem, BC2 32 42 9 16 25 52 A Hence, BC = 5 units By Pythagorus, theorem, 12 13 AB2 132 52 169 25 144 122 D Hence, AB = 12 units 3 4 Hence, area of shaded figure B 5 C = Area of ABC Area of BDC = 1 5 121 3 4 sq. units2 2 = 30 6 sq. units = 24 sq. units Answer: (b) 1.6 There are (2 x – 1) barrels of oil and each barrel contains (x + 1) liters of oil. Hence, total amount of oil in all the barrels = (2x – 1) (x + 1) liters Cost of oil is $( x + 2) per liter. Hence, the total cost of oil in all the barrels = $ 2x 1 x 1 x 2 = $ 2x2 2x x 1 x 2 = $ 2x2 x 1 x 2 = $ 2x3 x2 x 4x2 2x 2 = $ 2x3 5x2 x 2 Answer: (a) 1.7 A line passes through the points (a,2) and (3,1). Hence, the equation of the line is y 12 1 x 3a 3 1 y 1a 3 x 3 1 3y a 3x a 31 y 1 a 3 x 3 a 3 a 3 1 x a 6y a 3 a 3 y -intercept of this line is a 6 a 3 Given; y-intercept of this line is 1. Hence, a 6 1a 3 a 6 a 3 2a 9 9a 2 1 1 2 2 Hence, slope of this line = a 3 9 3 9 6 3 2 Answer: (d) 1.8 Let the height of the cylinder = h cm Diameter of iron ball = 7 cm Hence, radius of iron ball = 7 2 = 3.5 cm Volume of 12 iron balls = Volume of cylinder 124 3.53 72 h3 h 124 3.53 1 cm 3 72 h 14 cm Answer: (a) 1.9 Average speed = Totaldistance Total time Hence, the person who travels largest distance in least time will have highest average speed. Mary travels the highest distance in least time, and hence Mary has highest average speed. Answer: (b) 1.10 Weight of 20 children = weight of 12 adults Hence, weight of 5 children = weight of 3 adults Capacity of elevator = weight of 20 children = weight of 15 children + weight of 5 children = weight of 15 children + weight of 3 adults Hence, 3 adults can board the elevator with 15 children Answer: (a) 1.11 All the sides of a rhombus are equal. D C Given; one diagonal is equal to the side Hence, BD = AB = AD = BC = CD Hence, ABD and BCD are equilateral trianglesB Hence, A DAB = ABD = ADB = BDC = BCD = DBC = 60 Hence, ADC = ABC = 120 Hence, angles of rhombus are 60 and 120 Answer: (b) 1.12 Fraction left = 1 1 1 1 75 15 25 3 32 5 3 25 75 75 Answer: (c) 2.1 Line 2x y 1 0 is y 2x 1 Hence, its slope is 2 and y-intercept is 1. y 10 9 8 7 6 5 4 3 2 1 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10x -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 Answer: Coordinates of the points of intersection are (3,7) and ( 2, 3). 2.2 Peter purchases toys at the rate of 11 toys for $10. Hence, purchase price of one toy = $ 10 11 Peter sells the toys at the rate of 10 toys for $11. Hence, sale price of one toy = $ 11 10 Hence, percentage profit = 11 10 11 11 100 10 11 100%10 11 11 100% 121 100 % 21%10 10 11 Answer: 21% 2.3 Length of the semi-circular portion = 22 841m 132 m 7 2 Length of the racing track = 200 m + 132 m + 200 m + 132 m = 664 m = 0.664 km. Answer: 0.664 km. 2.4 Let the number of pizzas sold = n 30% of pizzas are large, hence (100% 30%) = 70% pizzas are small Hence, number of large pizzas sold =30 n100 A large pizza is sold for $5. Hence, amount of sale of large pizzas = $30 n 5100 Hence, number of small pizzas sold =70 n100 A small pizza is sold for $4. Hence, amount of sale of small pizzas = $70 n 4100 Total amount of sale = $817, hence 30 n 570 n 4 817100 100 150 280n 817100 430 n 817100 n 817100 190430 Answer: 190 pizzas. 2.5 Draw lines AC, CD and AD as shown in the figure. D Lizard 12 m C Insect 6 m A 4 m B D is the midpoint of the side, hence, C is the mid point of the side having length 6 m Hence, BC = 3 m ABC is a right angles triangle, hence by Pythagorus theorem AC2 AB2 BC2 42 32 16 9 25 52 Hence, AC = 5 m ACD is a right angles triangle, hence by Pythagorus theorem AD2 AC2 CD2 52 122 25 144 169 132 Hence, AD = 13 m Answer: = 13 m 3.1 (a) Let the time of traveling till the fuel tank becomes empty = t hours Fuel is leaking at the rate of 1 liter per hour Hence, quantity of fuel leaked in t hours = t liters Distance traveled at the speed of 100 km per hour = 100t km Fuel consumption rate of the car at 100 km per liter = 8 km per liter Hence, fuel consumed = 100t liters 8 Fuel in the tank at the start of the journey = 20 liters Hence, Fuel leaked + Fuel consumed = 20 liters t 100t208 108t208 t20 8 hours108 Hence, distance traveled = 10020 8 148.15 km 108 Answer: 148.15 km 3.1 (b) Let the time of traveling till the fuel tank becomes empty = T hours Fuel is leaking at the rate of 1 liter per hour Hence, quantity of fuel leaked in T hours = T liters Distance traveled at the speed of 50 km per hour = 50T km Fuel consumption rate of the car at 50 km per liter = 10 km per liter Hence, fuel consumed = 50T 5T liters 10 Fuel in the tank at the start of the journey = 20 liters Hence, Fuel leaked + Fuel consumed = 20 liters T 5T 20 6T 20 T20 10 hours6 3 Hence, distance traveled = 5010 166.67 km 3 Answer: 166.67 km 3.1 (c) Hence, at the speed of 100 km per hour, Peter can drive up to 148.15 km only, whereas at the speed of 50 km per hour, Peter can drive up to 166.67 km. His friend lives 160 km away. Hence, to reach his friends house with leaking fuel tank, Peter should drive at the speed of50 km per hour. Answer: 50 km per hour 3.2 (a) The triangular face of the building has side lengths 90 ft, 150 ft and 120 ft. 902 1202 8100 14400 22500 1502 Hence, the triangular faces are right angled triangles with hypotenuse 150 ft Hence, area of triangular face = 1 90 120 5400 sq. ft2 Length of the building is 100 ft Hence, volume of the building = 5400 100 = 540,000 cubic ft Answer: 540,000 cubic ft 3.2 (b) Floor is in the shape of a rectangle with sides 150 ft and 100 ft Hence, area of the floor = 150 100 = 15,000 sq. ft Answer: 15,000 sq. ft 3.2 (c) Surface area of walls excluding the floor = Area of two triangular faces + Area of two slanting rectangular walls = 2 5400 + 90 100 + 120 100 sq. ft = 31,800 sq. ft Answer: 31,800 sq. ft 3.3 (a) BCD is an isosceles D C triangle because CD = CB126Hence, CBD = 180 126 272 Answer: CBD = 27 3.3 (b) CDB = CBD = 27 (They A B are equal angles of the isosceles triangle BCD) DC and AB are parallel sides of the trapezoid Hence, DBA = CDB = 27 (Alternate angles) Answer: DBA = 27 3.3 (c) DAB + ADB + ABD = 180 (They are angles of triangle ABD) Hence, DAB = 180 ADB ABD = 180 90 27 = 63 Answer: DAB = 63 GRADE 9 ASSESSMENT OF MATHEMATICS Multiple-Choice Questions: Question no. 1.1 to 1.12 Short-Answer Questions: Question no. 2.1 to 2.5 Tasks: Question no. 3.1 to 3.3 Test Paper No. 5 PREPARED BY: Sanjiva Dayal (sanjivadayal@yahoo.com) Multiple-Choice Questions 1.1 Water is filled with a constant rate in the container shown in the figure. Which of the following graph shows the relationship between the height of water level versus time? (a) height time (b) height time (c) height time (d) height time 1.2 Slope of line A is m. m is a non-zero number. Line B is perpendicular to line A. Which of the following statement is always true? (a) Slope of line B is greater than m (b) Slope of line B is less than to m (c) Slope of line B is equal to m (d) Slope of line B and m have opposite signs A cylindrical vessel is partly filled with water. The diameter of the vessel is 12 cm. A ball of diameter 6 cm is dropped into the vessel such that the ball is completely dipped in water. By how many cm will the surface of water rise? (a) 0.5 cm (b) 1 cm (c) 2 cm (d) 3 cm 1.4 Which natural number is 80% of the next natural number? (a) 3 (b) 4 (c) 6 (d) 8 1.5 Peter and his 15 friends went to a coffee shop. The total bill amount was $114.40. Peter paid for himself and 5 of his friends. How much did Peter pay? (a) $36.80 (b) $38.60 (c) $42.90 (d) $43.20 1.6 A man takes 150 steps in walking 120 meters. He takes 3 steps in one second. What is his speed? (a) 1.2 meter per second (b) 2.4 meter per second (c) 3.6 meter per second (d) 4.2 meter per second A train travels at the speed of 3x2 xy 2y2 km per hour for x y hours and at the speed of x y km per hour for 2x2 xy 3y2 hours. What is the total distance traveled by the train? (a) 5x3 8x2y 7xy2 y3 km (b) 5x3 5x2y 3xy2 y3 km (c) 5x3 3x2y 4xy2 y3 km (d) 5x3 3x2y 5xy2 y3 km 1.8 Which of the following statements is always true for all isosceles right-angled triangles? (a) All isosceles right-angled triangles are congruent (b) All isosceles right- angled triangles have same area (c) All isosceles right-angled triangles are similar (d) All isosceles right-angled triangles have same perimeter 1.9 What is the value of x? x (a) 100 80140(b) 120 20(c) 140 (d) 150 1.10 From 84 boys of the schools, three-seventh were selected for school sports and were divided equally into six teams. How many boys are there in each team? (a) 4 (b) 6 (c) 7 (d) 8 A triangular board is shown in the figure. What is A the height AD? (a) 6 units 9 12 (b) 6.5 units (c) 7 units (d) 7.2 units B D 15 C 1.12 20 men working 12 hours a day can complete a piece of work in 60 days. How many men can complete the same piece of work in 90 days working 8 hours a day? (a) 15 (b) 18 (c) 20 (d) 22 Short-Answer Questions 2.1 A tent is in the shape of a cone. Tent is made of thick canvas cloth. The canvas cloth costs $7 per sq. ft. What is the cost of the cloth that is required to make the tent? (All dimensions in the figure are in ft) (Use 22 ) 7 12 9 Show your work Answer: $______ 2.2 Figure ABC is a right-angled triangle, right angled at C. D is B the midpoint of side AC. E is the midpoint of side BC. Length of side AB is 4 units. What is the value of AE2 BD2 . E 4 C D A Show your work Answer: ____ sq. units There are two vessels. First vessel contains 10 liters mixture of alcohol and water in the ratio 5:3. Second vessel contains 5 liters mixture of alcohol and water in the ratio 7:5. The contents of both the vessels are poured in a third vessel that was empty. What is the percentage of alcohol in the third vessel? Show your work Answer: ______ % 2.4 The minute hand of a clock is 7 cm long. What is the distance covered by the tip of the minute hand in 15 minutes? (Use 22 ) 7 Show your work Answer: ____ cm Three points A, B, C are shown on the graph. Two of these points are joined to form three lines, AB, BC and AC. (a) Which of these lines has the greatest positive slope? (b) Which of these lines has the greatest y-intercept? (b) Which of these lines has the greatest x-intercept? y B A C x Show your work Answer: Line that has the greatest positive slope is AB BC AC Line that has the greatest y-intercept is AB BC AC Line that has the greatest x-intercept is AB BC AC Tasks 3.1 A pizza shop sells pizzas and ice creams. After 11:00 pm, the shop charges night fees per person but gives 25% discount on pizza and ice cream. A group of n persons want to know the total amount paid by them, P, in dollars, for eating p pizzas and m ice creams. The shop manager told them the formula of P after 11:00 pm. The formula is given below. P = 1.25n + 3.75p + 2.25m (a) What the number 1.25 in the formula stands for? Answer: _____________________________________________________________ Show your work (b) What the number 3.75 in the formula stands for? Answer: _____________________________________________________________ Show your work (c) What the number 2.25 in the formula stands for? Answer: _____________________________________________________________ Show your work (d) What is the formula of P before 11:00 pm? Answer: P = _______________________ Show your work (e) If John eats 1 pizza and 1 ice cream only, then should he eat before 11:00 pm or after 11:00 pm to save money? Answer: Before 11:00 pm After 11:00 pm Show your work 3.2 Diagonals of a rhombus are 6 cm and 8 cm long. (a) Draw both the diagonals and the four sides of the rhombus on the grid? = 1 cm (b) Calculate the length of the sides of the rhombus. Answer: _____ cm Show your work (c) Calculate the perimeter of the rhombus. Answer: _____ cm Show your work (d) Calculate the area of the rhombus. Answer: _____ sq. cm Show your work 3.3 In the given figure, AD = BD = CD and BDC = x . C (a) Write ADC in terms of x.xAnswer: ADC = ____ A D B Show your work. Explain your answer. (b) Write DAC in terms of x. Answer: DAC = ____ Show your work. Explain your answer. (c) Write DBC in terms of x. Answer: DBC = ____ Show your work. Explain your answer. (d) What is the measure of ACB? Discuss whether ACB depends on x or not? Answer: ACB = ____ Show your work. Explain your answer. ANSWERS 1.1 When water is filled with a constant rate, the height of the water level will rise faster in the container having smaller area. The bottom part of the container has the largest area. Area of the top part is smaller than the bottom part and the middle part has the least area. Hence, rate of increase of water level will be fastest in the middle part. Rate of rise of water level in the top part will be slower than the middle part and the rate of rise of water level is slowest in the bottom part. Hence, when the container is filled, slope of the graph of height of water level increases in the middle part and decreases in the top part. Answer: (b) 1.2 Line B isperpendicular to line A Hence, slope of line B = 1 m Hence, slope of line B and m have opposite signs. Answer: (d) 1.3 Diameter of the vessel = 12 cm Hence, radius of the vessel = 12 2 = 6 cm Diameter of the ball = 6 cm Hence, radius of the ball = 3 cm Let the rise in surface of water = h cm Volume of the ball = volume of water displaced 4 33 62 h3 h4 33 1 1 cm 3 62 Answer: (b) 1.4 Let the natural number = n This number is 80% of the next natural number Hence, n80 n 1100 n 80 n 80 100 100 n 80 n 80 100 100 20 n 80 100 100 n 4 Answer: (b) 1.5 Total number of persons = 16 (Peter and his 15 friends) Bill amount = $114.40 Hence, share of 1 person = $114.40 $7.1516 Peter paid for the share of 6 persons (himself and 5 of his friends) Hence, amount paid by Peter = $7.15 6 = $42.90 Answer: (c) 1.6 The man takes 3 steps in one second Hence, time taken to take 150 steps = 150 seconds = 50 seconds 3 Hence, he walks 120 meters in 50 seconds Hence, his speed = 120 meter per second = 2.4 meter per second 50 Answer: (b) 1.7 Total distance traveled by the train = 3x2 xy 2y2 x y x y 2x2 xy 3y2 km = 3x3 x2y 2xy2 3x2y xy2 2y3 2x3 x2y 3xy2 2x2y xy2 3y3 = 5x3 3x2y 5xy2 y3 Answer: (d) 1.8 In all isosceles right-angled triangle, angels are 90 , 45 and 45 . Hence, they are all similar Answer: (c) 1.9 a = 180 140 = 40 (Supplementary angles) x y = 80 + a = 80 + 40 = 120 (External angle of the triangle) x = 20 + y = 20 + 120 = 140 80 14020 y a (External angle of the triangle) Answer: (c) 1.10 Three-seventh of 84 students were selected Hence, number of selected students = 3 84 367 Selected students were divided equally into six teams Hence, number of students in each team = 36 6 = 6 Answer: (b) 1.11 In ABC,A AB2 AC2 92 122 81 144 225 152 BC2 Hence, ABC is a right angled triangle with 9 12 BAC = 90 Hence, area of ABC = 1 2AB AC B D 15 C Also, area of ABC =1 BC AD2 Hence, 1 BC AD1 AB AC2 2 15 AD 9 12 9 12 7.2 unitsAD15 Answer: (d) 1.12 20 men complete the work working 12 hours a day for 60 days Hence, 20 men complete the work working = 12 60 hours = 720 hours 8 hours a day for 90 days = 8 90 hours = 720 hours Hence, number of hours is the same. Hence, 20 men will complete the work working 8 hours a day for 90 days Answer: (c) 2.1 Let the slant height of the cone = L ft By Pythagorus theorem, L2 122 92 144 81 225 152 Hence, L = 15 ft Radius of the tent = r = 9 ft 12 Hence, curved surface area of the tent 9 = rL = 22 9 15 sq. ft7 Cost of 1 sq. ft of canvas cloth = $7 Hence, cost of cloth = $22 9 15 7 $29707 Answer: $2970. 2.2 AE2 BD2 AC2 CE2 CB2 CD2 (By Pythagorus theorem) 2 CB2 CE2 CD2AC AB 2 CB2 AC2 2 2 (By Pythagorus theorem)(D and E are midpoints) AB 2 CB2 AC2 4 AB 2 AB2 4 (By Pythagorus theorem) 4 2 42 4 16 4 20 sq. units Answer: 20 sq. units. 2.3 Quantity of alcohol in 10 liter mixture = 5 5 3 105 1025 liter 8 4 Quantity of alcohol in 5 liter mixture = 7 535 liter7 5 12 Hence, total quantity of alcohol in the third vessel = 25 35 25 3 35 110 55liter 4 12 12 12 6 Quantity of mixture in the third vessel = 10 + 5 liters = 15 liters. Hence, percentage of alcohol in the third vessel = 55 1 100%550% 611%6 15 9 9 Answer: 611%9 2.4 Distance covered by the tip of the 7 cm long minute hand in 15 minutes = one-fourth of the circumference of the circle of radius 7 cm = 1 222 7 cm 4 7 = 11 cm Answer: 11 cm. 2.5 y B A C x Answers: (a) Line BC has the greatest positive slope. (b) Line AC has the greatest y- intercept. (c) Line AC has the greatest x-intercept? 3.1 (a) P = 1.25n + 3.75p + 2.25m When n increases by 1, P increases by $1.25. Answer: $1.25 is the night fees per person. 3.1 (b) When p increases by 1, P increases by 3.75 Answer: $3.75 is the cost of 1 pizza. 3.1 (c) When m increases by 1, P increases by 2.25 Answer: $2.25 is the cost of 1 ice cream. 3.1 (d) Before 11:00 pm, there is no night fees. There is discount of 25% after 11:00 pm Cost of 1 pizza after 11:00 pm = $3.75, which is 75% of the price before 11:00 pm Hence, cost of 1 pizza before 11:00 pm = $ 100 3.75 = $575 Cost of 1 ice cream after 11:00 pm = $2.25, which is 75% of the price before 11:00 pm Hence, cost of 1 ice cream before 11:00 pm = $100 2.25 = $375 Hence, formula of P before 11:00 pm is P = 5p + 3m Answer: P = 5p + 3m 3.1 (e) If John eats 1 pizza and 1 ice cream before 11:00 pm, he will have to pay = $5 + $3 = $8 If John eats 1 pizza and 1 ice cream after 11:00 pm, he will have to pay = $1.25 + $3.75 + $2.25 = $7.75 $7.75 is less than $8 Answer: John should eat after 11:00 pm. 3.2 (a) Diagonals of a rhombus are perpendicular and they bisect each other. x 3 cm 4 cm 3.2 (b) Let length of the side = x By Pythagorus theorem, x2 32 42 9 16 25 52 Hence, x = 5 cm Answer: 5 cm 3.2 (c) Hence, perimeter of rhombus = 4 5 = 20 cm Answer: 20 cm 3.2 (d) Area of rhombus = 1 Product of diagonals =1 8 6 24 sq. cm 2 2 3.3 (a) ADC = 180 - x (SupplementaryC angles) Answer: ADC = 180 - x 3.3 (b) Since AD = DC, hence DAC = DCAx DAC + DCA + ADC = 180 A D B (Angles of a triangle) Hence, 2 DAC + 180 - x = 180 xDAC2 Answer: DAC x 2 3.3 (c) Since DB = DC, hence DCB = DBC DCB + DBC + BDC = 180 (Angles of a triangle) Hence, 2 DBC + x = 180 xDBC 902 Answer: DBC 90 x 2 3.3 (d) ACB = ACD + DCB = DAC + DBC = x 90x 90 . 2 2 Answer: ACB = 90 . Hence, ACB does not depend on x. GRADE 9 ASSESSMENT OF MATHEMATICS Multiple-Choice Items Test Paper No. 6 PREPARED BY: Sanjiva Dayal (sanjivadayal@yahoo.com) Six liters sugar solution contains 8% sugar and rest is water. One liter of water evaporated. What is the percentage of sugar in the remaining solution? The radius and height of a cylinder are both equal to the radius of a sphere. What is the ratio of the volume of the sphere to the volume of the cylinder? 8% sugar solution (a) 24%5 (b) 81%5 (c) 93%5 (d) 63%5 (a) 1:2 (b) 3:2 (c) 4:3 (d) 3:1 4. John buys 30 chairs, all at the same price. He sells 20 of them at a profit of 16% and has to sell the remaining 10 at a loss of 4%. What is his profit percentage in the deal? 2. Peter and Paul enter into a partnership business with capital $15,000 and $21,000 respectively. The profit from the business is to be divided in the proportion of their capitals. Peter received $3040 from the profit. How much did Paul receive from the profit? (a) 12% (b) 14% (c) 62%3 (d) 91%3 (a) $4180 (b) $4256 (c) $4378 (d) $4398 Due to global warming, Gangotri glacier in India is shrinking at the rate of 30 meters annually. What is the average shrink in one second? A wet cloth was put in the drying machine. The weight of the cloth changes with time as shown in the graph. 1.7 1.65 1.6 1.55 1.5 012 3 45 Time (minutes) What was the weight of the water present in the cloth before drying? (a) 5.7 105m (b) 2.3 105m (c) 3.5 104m (d) 9.5 107m (a) 50 grams (b) 100 grams (c) 125 grams (d) 150 grams 6. The sum of the ages of father and son is 50 years. When the son will attain the father’s present age, then the sum of their ages will be 102 years. What is the present age of the son? 8. The length, width and height of a rectangular prism are each decreased by 10%. What is the percentage decrease in the volume of the rectangular prism? (a) 8 years (b) 10 years (c) 12 years (d) 15 years (a) 30% (b) 28.8% (c) 27.1% (d) 26.9% 9. There are a3b2 3 boxes of chocolates. Each box contains a2b3 4 chocolates. These chocolates are distributed equally among a4b5 2 children. How many chocolate each child gets? (a) a8b7 (b) a7b6 9b7(c) a (d) a9b8 Sides of an equilateral triangle are (x + 2) cm, (2 x – 3) cm and (2x – 3) cm. What is the perimeter of the triangle? In an isosceles triangle of fixed perimeter, the length of the equal sides is y cm and the length of the third side is x cm. y y (a) 15 cm (b) 18 cm (c) 21 cm (d) 24 cm 11. Which of the following pair of lines cannot be parallel? (a) Two sides of a quadrilateral (b) Two sides of a pentagon (c) Two chords of a circle (d) Two diameters of a circle x The variation of y withx is shown in the graph. 30 25 20 15 10 5 0 0 5 10 15 20 25 x (cm) What is the perimeter of the isosceles triangle? (a) 30 cm (b) 40 cm (c) 50 cm (d) 60 cm 13. A cow is given rich diet and gains 15% in weight. The cow is then put on a poor diet and looses 20% in weight. What is the overall change in weight of the cow? A regular polygon has fixed number of sides. If its side length is changed, its perimeter changes as shown in the graph. There are 3x2 x 2 words in a book. How (a) Looses 5% weight (b) Looses 8% weight (c) Looses 10% weight (d) Gains 6% weight many words are there in 2x 3 copies of the book? 25 20 15 10 5 0 0123 Side length (cm) What is the number of sides of the polygon? (a) 7 (b) 8 (c) 9 (d) 10 15. Figure ABCD is a parallelogram and L is a point on the side CD such that CL = 2DL. A B D L C What is the ratio of the area of the triangle ABL to the area of the parallelogram ABCD? (a) 6x3 7x2 7x 6 (b) 6x3 11x2 7x 6 (c) 6x3 7x2 x 6 (d) 3x3 11x2 7x 6 17. Diameter of the wheels of a car is d, in meters. When the wheels of the car are rotating at the rate of n revolutions per second, the speed of the car v, in meters per second, is given by the formula v dn The variation of speed v with n is shown in the graph. 35 30 25 20 15 10 5 0 (a) 1:2 (b) 1:3 (c) 1:4 (d) 2:3 01 23 n (revolutions per second) What is the diameter of the wheels? (a) 2 m (b) 2.5 m (c) 3 m (d) 3.5 m John met with an accident and was brought to the hospital. 100 ml of glucose was immediately injected into him and the next 100 ml was drip injected slowly over the period of 30 minutes as shown in the graph. Peter is a taxi driver. Fuel tank of his taxi has capacity of 50 liters of fuel. As soon as the fuel in the tank drops to 10 liters, Peter fills the tank to the full capacity. Which of the following graph correctly shows the quantity of fuel in the tank against the distance traveled? 200 (a) 150 100 50 0 0 5 10 15 20 25 30 Time (minutes) 50 40 30 20 10 0 John’s condition stabilized after consuming 160 ml of glucose. After how much time John’s condition stabilized? (b) (a) 12 minutes (b) 14 minutes (c) 16 minutes (d) 18 minutes 19. Surface area of a sphere is S sq. units and its volume is V cubic cm. What is the relationship between S and V? 0 500 1000 1500 2000 Distance (km) 50 40 30 20 10 0 0 500 1000 1500 2000 Distance (km) (c) (a) S2 36 V (b) V3 36 S2 (c) S3 36 V3 (d) S3 36 V2 50 40 30 20 10 0 0 500 1000 1500 2000 Distance (km) (d) 50 40 30 20 10 0 0 500 1000 1500 2000 Distance (km) Peter is an engineer and he is doing calculations for designing a bridge. 5 0 01 23 45 Diameter (cm) He has to simplify the following expression: 4 x2 xy9 y2 2 x3 y9 4 3 2 What is the value of this expression? (a) 8 x3 xy2 27 y3 27 8 (b) 8 x3 x2 y27 y3 27 8 (c) 8x3 27y3 27 8 (d) 8x3 2x2y 3xy2 27y3 27 3 2 8 Which of the following graph correctly shows the relationship between the circumference of a circle and its diameter? (a) 15 10 (b) 15 13 11 9 7 5 3 1 -1 01 23 45 Diameter (cm) (c) 15 13 11 9 7 5 3 1 -1 01 23 45 Diameter (cm) (d) The interior angles of a polygon are in the ratio 2:4:5:6:6:7. What is the greatest angle? Peter is participating in 20 km marathon walk. Distance moved by Peter with the number of steps he walks is shown in the graph below. 15 13 11 9 7 5 3 1 -1 01 23 45 Diameter (cm) (a) 144 (b) 156 (c) 168 (d) 172 200 150 24. In an adult, resting heart rate is normally about 70 beats per minute. However, the heart can beat up faster when a person is exercising vigorously. The maximum heart rate M, in beats per minute, of a person of age N, in years, is shown in the graph. 0 012345 Number of steps 200 190 180 170 160 150 How many steps did Peter take during the Marathon walk? (a) 500 steps (b) 5000 steps (c) 5500 steps (d) 50,000 steps 20 25 30 35 40 45 50 55 60 N (years) 26. Look at the coordinate plane given below. What is the formula of H in terms of N? (a) H = 200 + N (b) H = 220 + N (c) H = 200 N (d) H = 220 N 100 50 y (4,7) (2,3) (6,x) 0 x What is the value of x ? (a) 4 (b) 5 (c) 6 (d) 7 A quadrilateral is drawn on the coordinate plane. y Jennifer has $5000. She invested some of his money at 6% per annum and the rest amount at 9% per annum interest. In one year she received interest of $390. How much money she invested at 6% interest? 0 x How many sides of this quadrilateral has positive slope? (a) 1 (b) 2 (c) 3 (d) 4 28. The ticket of a circus is $2 for children and $3 for adults. On Monday, 320 persons watched the circus and the total collection was $830. What was the number of children who watched the circus on Monday? (a) $2000 (b) $2100 (c) $2300 (d) $2700 30. A tank is being filled with water at a constant rate. 4 of the tank is filled in 1 hour. In how much time9 the rest of the tank will be filled? (a) 110 (b) 130 (c) 150 (d) 190 (a) 135 minutes (b) 1 hour (c) 75 minutes (d) 90 minutes 31. In the following figure AB = AC. A x 2x 40 50 D B C E What is the measure of BAC? (a) 50 (b) 60 (c) 70 (d) 80 32. The minute hand of a clock rotates through angle A in time T. What is the formula of A, in degrees, in terms of T, in minutes? 1112 1 10 2 9 3 8 4 7 6 5 (a) A 6T (b) A 60T (c) A T 6 (d) A T 60 ANSWERS 1. 6 liters of solution contains 8% sugar and rest is water. Hence, quantity of sugar = 6 8 12 liter100 25 1 liter of water evaporated, hence quantity of remaining solution = 6 liters – 1 liter = 5 liters Hence, percentage of sugar in the remaining solution = 12 1 100%48% 93%25 5 5 5 Answer: (c) 2. Ratio of share of Peter to share of Paul = 15000:21000 = 5:7 Share of Peter = $3040 Hence, share of Paul = 7 3040 $42565 Answer: (b) 3. Let radius of cylinder = height of cylinder = radius of sphere = r units Hence, ratio of volume of sphere to volume of cylinder =4 r3 : r2r = 4:33 Answer: (c) 4. Let the cost price of each chair = x units 20 chairs are sold at the profit of 16%. Hence, sale price of these 20 chairs = 20x16 20x20 116 x116x units100 100 5 10 chairs are sold at a loss of 4%. Hence, sale price of these 10 chairs = 10x4 10x48 x units100 5 Hence, total sale price = 116x 48x 164x units5 5 5 Total cost price = 30x units Hence, profit percentage 164x 30x5 100%30x 164 150100%30 5 14 2%3 91%3 Answer: (d) 5. 1 year has 365 days. 1 day has 24 hours, 1 hour has 60 minutes and 1 minute has 60 seconds. Hence,1 year = 365 24 60 60 seconds Glacier shrinks 30 meters in 1 year. Hence, average shrink in 1 second = 30 m 9.5 10 7 m365 24 60 60 Answer: (d) 6. Let the present age of the son = x years Hence, present age of father = (50 – x) years Son will attain father’s present age after (50 – 2x) years Father’s age after (50 – 2x) years will be = (50 – x) years + (50 – 2x) years = (100 – 3x) years Sum of their ages is 102. Hence, (50 – x) + (100 – 3x) = 102 150 – 4 x = 102 4x = 150 – 102 4x = 48 x = 12 Answer: (c) 7. Weight of wet cloth before drying = 1.7 kg. During drying, the weight of the cloth decreases due to loss of water. When the cloth is completely dry, the weight becomes constant and the graph becomes horizontal. Weight of dry cloth = 1.55 kg Hence, weight of water in the wet cloth = 1.7 1.55 kg = 0.15 kg = 0.15 1000 grams = 150 grams Answer: (d) 8. Let the length, width and height of the rectangular prism be L, W and H respectively. Hence, volume = L W H After decrease in dimensions by 10%, length = L – 0.1L = 0.9L width = W – 0.1W = 0.9W height = H – 0.1H = 0.9H Hence, volume after decrease in dimensions = 0.9L 0.9W 0.9H = 0.729 L W H Hence, percentage decrease in volume = L W H 0.729 L W H100%L W H = 1 0.729 100% 27.1% Answer: (c) 9. There are a3b2 3 boxes of chocolates. Each box contains a2b3 4 chocolates. Hence, total number of chocolates = a3b2 3 a2b3 4 These chocolates are distributed equally 2 children.a4b5among Hence, number of chocolates each child gets 3 a2b3 4 = a3b2 a4b5 2 = a3 3b2 3a2 4b3 4 a4 2b5 2 = a9b6a8b12 8b10a a 9 8b6 12 = a8b10 = a17b18 a8b10 = a17
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