Official Guide Explanation:
Problem Solving #178




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Solution and Metadata

Question: 178
Page: 177
Difficulty: 6 (Moderately Difficult)
Category 1: Arithmetic > Sets > 3+ sets
Category 2: Word Problems > Sets >

Explanation: The total number of students listed in the chart is 40 + 30 + 25 = 95. However, some of those students are double - counted: those students who, for instance, are in both Chess and Drama were counted in each of those categories. To remedy that problem, we need to subtract the number of students who were in each pair of clubs. Since the question tells us that there were 10, 5, and 6 students in various pairs of clubs (and no students in all three), the actual number of students is given by 95 - 10 - 5 - 6 = 74, choice (C).

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