GRE-Math-Questions-to-Know-by-Test-Day-2nd-Edition_pag217

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286. (D)
 =z y
x
1.2
2
 
 =zx y1.22 
 =x y
z
1.22 
= ±x y
z
1.2 
287. (D)
 = + + − − −x10 10(1 (2 3 ) )1 1 1 = + +
− −
10 1 2 1
3
1 1
 = +
− −
10 1 7
3
1 1
 = +
−
10 1 3
7
1
 = 
−
10 10
7
1
 = 10 7
10
 = 7 
288. (A) Let x = number of pounds of $2.50 per pound candy. Then 90 – x = number 
of pounds of $3.75 per pound candy. Make a chart to organize the information in the 
question.
 Price Number of Pounds Value
 $2.50 x $2.50x
 $3.75 90 – x $3.75(90 – x)
 $3.00 90 $3.00(90)
 The value of the candy before it is mixed should equal the value after it is mixed. 
Using the information in the chart, set up an equation and solve for x (omitting units for 
convenience):
 + − =x x2.50 3.75(90 ) 3.00(90) 
+ − =x x2.50 337.50 3.75 270.00 
 − = −x1.25 67.5 
 =x 54 
 Tip: Think before you begin. If you use half of each type of candy, then the price would 
be the average of $2.50 and $3.75, which is about $3.13, so you know that to bring the 
price down to $3.00 per pound, you will need more than 45 pounds (half of 90 pounds) of 
the $2.50 candy. So you can eliminate choices (C), (D), and (E) right away. You can check 
(A) and (B) in the first equation to determine that (A) is the correct response.
06_McCune_Answer.indd 208 2/21/22 4:49 PM