Official Guide Explanation:
Data Sufficiency #107

 

 

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.

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Solution and Metadata

Question: 107
Page: 282
Difficulty: 4 (Moderately Easy)
Category 1: Arithmetic > Discrete Probability >
Category 2: Arithmetic > Fractions >

Explanation: Since there are three colors of chips in the box, the probability that a selected chip is white or blue is 1 minus the probability that it is red.

Statement (1) is insufficient: the probability of white or blue is the sum of the probability of white and the probability of blue, and this only gives us one of those. Statement (2) is sufficient: the probability we're looking for is (1 - red), so given the probability of red, we can find the probability of white or blue. Choice (B) is correct.

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