Official Guide Explanation:
Data Sufficiency #5




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Solution and Metadata

Question: 5
Page: 273
Difficulty: 4 (Moderately Easy)
Category 1: Word Problems > Other >
Category 2: Geometry > Lines >

Explanation: It might be helpful to draw a diagram for this question. Even better, view it as a system of linear equations. Statement (1) tells you that L - J = 21, where L and J are the mile markers at exits L and J. It tells you nothing about K, so it's insufficient. Statement (2): M - K = 26. Nothing about L, so it's insufficient.

Taken together, the statements are still insufficient. You have two equations with four variables: that's not enough to solve for any of the variables. Since there are no variables in common between the two equations, there's no chance you can combine them in some way to find the value of K - L. Choice (E) is correct.

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