Section: Math Section 2

35) Jack has b blueberries. He uses 30 percent of the blueberries to make muffins, each of which requires m m blueberries. He uses the rest of the blueberries to make pies, each pie of which requires p blueberries. Which of the following describes the number of blueberry pies Jack can make?

1. ^3b/_10m
2. ^3b/_10p
3. ^7b/_10m
4. ^7b/_10p
5. ^7bp/₁₀

Since there are variables in the answer choices, picking numbers is a good strategy for solving this problem. Since the question deals with percentages, 100 is a good number to pick for b. Jack uses 30% of 100 blueberries, that is 100(.3) = 30 blueberries to make muffins. You don’t need to know how many blueberries it takes to make a muffin or how many muffins Jack makes. All you need to know is how many blueberries are available to make pies with. 100 — 30 = 70 blueberries are available to make pies with. If each pie requires 7 blueberries (that is, if p = 7), Jack can make 10 pies. Plug b = 100 and p 7 into the answer choices to see which yields 10.

^7b/_10p = ⁷⁽¹⁰⁰⁾/₁₀₍₇₎ = ⁷⁰⁰/₇₀ = 10.