Official Guide Explanation:
Problem Solving #115




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Solution and Metadata

Question: 115
Page: 168
Difficulty: 5 (Moderate)
Category 1: Algebra > Equations >
Category 2: Arithmetic > Percents > Percent Change
Category 3: Word Problems > Discount >

Explanation: There are several equations you can set up from this question; the key is to do so efficiently, which will come with practice. If Mary's income is 60 percent more than Tim's, m = 1.6t. If Tim's is 40 percent less than Juan's, t = 0.6j. Finally, another way of writing the question is to look for the value of x in m = (((x)/100))j. You'll need to get m and j in the same equation, so look for a way to combine the first two. If you substitute 0.6j for t in the first equation, you're left with m = 1.6(0.6j) = 0.96j. Putting this equation together with m = (((x)/100))j, it's evident that x = 96, choice (C).

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