Official Guide Explanation:
Data Sufficiency #38

 

 

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.

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Solution and Metadata

Question: 38
Page: 155
Difficulty: 5 (Moderate)
Category 1: Word Problems > Work Problems > 2 inputs
Category 2: Word Problems > Rate Problems > Combined Rate

Explanation: To find the amount of time it would take for both machines to produce the lot of cans, you need the rate at which machine Y runs. Statement (1) is sufficient: we know the rate at which X runs, and if they are equal, we also know Y's rate. Statement (2) is also sufficient: if it takes X twice as long as it takes X and Y combined to produce the lot, that means it takes 1 hour for X and Y combined to produce the lot, which is all the information needed to determine the answer. Choice (D) is correct.

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