Official Guide Explanation:
Problem Solving #39

 

 

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.

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Solution and Metadata

Question: 39
Page: 157
Difficulty: 5 (Moderate)
Category 1: Geometry > Coordinate Geometry > Distance

Explanation: There are a number of ways to do this question without going through the extremely arduous process of using multiple equations, all of which involve the distance formula. Most easily, you could eyeball the diagram: a point that is closer to Q than P should be around (2,1), choice (B). To be more precise, recognize that, horizontally, P and Q are three units apart, while vertically, they are also three units apart. Thus, if you want a point that is twice as far from P as it is from Q, you want a point that is 2 units away from P and 1 unit away from Q in both directions. That method gives you the same result: choice (B), (2,1).

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