M7MBA wrote:The positive numbers w, x, y, and z are such that x is 20 percent greater than y, y is 20 percent greater than z, and w is 20 percent less than x. What percent greater than z is w ?
A. 15.2%
B. 16.0%
C. 20.0%
D. 23.2%
E. 24.8%
20% = 1/5.
The prompt requires that 20% be taken 3 times, implying that we must multiply 3 times by 1/5.
To keep the numbers as small as possible, let z = 5*5*5 = 125.
Let z = 125.
Since y is 20% greater than z, y = 125 + (1/5 of 125) = 125+25 = 150.
Since x is 20% greater than y, x = 150 + (1/5 of 150) = 150+30 = 180.
Since w is 20% less than x, w = 180 - (1/5 of 180) = 180-36 = 144.
What percent greater than z is w?
Percent increase from 125 to 144 = Difference/Smaller * 100 = (144-125)/125 * 100 = (19/125) * 100 = (19/5) * 4 = 76/5 = 15.2.
The correct answer is
A.
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