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## Official Guide Explanation:Problem Solving #200

Background

This is just one of hundreds of free explanations I've created to the quantitative questions in The Official Guide for GMAT Review (12th ed.). Click the links on the question number, difficulty level, and categories to find explanations for other problems.

These are the same explanations that are featured in my "Guides to the Official Guide" PDF booklets. However, because of the limitations of HTML and cross-browser compatibility, some mathematical concepts, such as fractions and roots, do not display as clearly online.

Question: 200
Page: 181
Difficulty: 7 (Very Difficult)
Category 1: Arithmetic > Sets > 2 sets
Category 2: Word Problems > Sets >
Category 3: Arithmetic > Percents > other

Explanation: First, convert all the percents into numbers, which is straightforward when the total number of researchers is 50. 50(0.4) = 20 will be assigned to team A and 50(0.6) = 30 will be assigned to team B. 50(0.7) = 35 prefer team A while 50(0.3) = 15 prefer team B. To limit the number of researchers who aren't assigned to the team they would like, assign 20 of the 35 researchers who would prefer team A to team A, leaving 15 researchers who prefer team A but can't be assigned to it. That leaves those 15 unlucky researchers along with the 15 who preferred team B to be assigned to team B. That's a total of 15 researchers who weren't assigned to the team they preferred, choice (A).

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