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## Official Guide Explanation:Data Sufficiency #48

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: 48
Page: 277
Difficulty: 4 (Moderately Easy)
Category 1: Arithmetic > Ratio and Proportion >
Category 2: Arithmetic > Percents > other

Explanation: Statement (1) is insufficient. The question starts by asking the relationship between two variables--June transactions made by each of two salespeople. This statement adds a third: May transactions by Y. If we call June transactions by X xj and May transactions by Y ym, we can set up an equation:

xj = 1.5ym

Statement (2) is also insufficient. It says nothing about X. It does give us another relationship:

yj = 1.25ym

Taken together, the statements are sufficient. We're looking for ((xj)/(yj)), and each of the statements gives us one of those in terms of Y's May transactions. We can plug in each of those equations:

((xj)/(yj)) = ((1.5ym)/(1.25ym)) = ((1.5)/(1.25)) = (6/5)

Choice (C) is correct.

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