Official Guide Explanation:
Problem Solving #49




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Solution and Metadata

Question: 49
Page: 159
Difficulty: 5 (Moderate)
Category 1: Arithmetic > Properties of Integers > Other
Category 2: Algebra > Inequalities > other

Explanation: Given a compound inequality, you can simplify it like any other inequality, you just have to remember to do the same thing to all three parts instead of only two. In this case, since you're interested in n, solve for n:

1 < 5n + 5 < 25

-4 < 5n < 20

((-4)/5) < n < 4

Thus, the range for n limits it to four integers: 0, 1, 2, and 3, so the correct choice is (B).

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