Official Guide Explanation:
Data Sufficiency #40




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Solution and Metadata

Question: 40
Page: 276
Difficulty: 5 (Moderate)
Category 1: Word Problems > Data Interpretation >

Explanation: To find the value of x, you'll need to find the distance between R and T. Note that no other distances--for instance the distance between R and S combined with the distance between S and T--would be sufficient to answer the question, since we don't know if that would be the most direct route between R and T.

Statement (1) compares the lengths of the routes betwen S and T and S and R, which would allow you to solve for y, but does nothing to help you solve for x. Statement (2), however, is sufficient: the distance between T and U is 69, so if 69 is 1.5 times the distance beween R and T, you can find that distance. Choice (B) is correct.

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