Bunuel wrote:
If w is 40 percent less than x, x is 40 percent less than y, and z is 46 percent less than y, then z is greater than w by what percent of w?
A. 4%
B. 18%
C. 36%
D. 40%
E. 50%
Kudos for a correct solution.
800score Official Solution:(E) In order to answer this question, you need to get the value of all the variables in terms of y: z = 0.54y, x = 0.6y, and w = 0.6x = 0.6(0.6y) = 0.36y.
Now, compare the two. To find a percent difference between two numbers or variables, you take one and subtract it from the second, and then divide by the second. The amount being subtracted is usually the one following "than" in the question. Therefore: (z – w)/w = (0.54y – 0.36y)/(0.36y) = 0.18y/(0.36y) = 0.5.
z is 50% larger than w.
_________________