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Official Guide Explanation:Data Sufficiency #4

Background

This is just one of hundreds of free explanations I've created to the quantitative questions in The Official Guide for GMAT Quantitative Review (2nd 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: 4
Page: 153
Difficulty: 4 (Moderately Easy)
Category 1: Word Problems > Geometry Problems >
Category 2: Algebra > Linear Equations-Two Unk >
Category 3: Geometry > Quadrilaterals >

Explanation: The perimeter of a rectangle is given by 2l + 2w. Statement (1) is insufficient: if we knew the width of the rectangle, we could add it to 40, but we don't. Statement (2) is sufficient. If l + w = 25, then 2(l + w) = 2(25) = 50, the perimeter of the rectangle. (B) is the correct choice.

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