Official Guide Explanation:
Problem Solving #175




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Solution and Metadata

Question: 175
Page: 85
Difficulty: 6 (Moderately Difficult)
Category 1: Geometry > Quadrilaterals >
Category 2: Arithmetic > Ratio and Proportion >
Category 3: Word Problems > Geometry Problems >

Explanation: This question is deceptive, but not as hard as it looks. If there are no restraints on what the width of the strip could be (for instance, that the length or width of the countertop or the inlay must be an integer), then the width could be any number. Simply knowing the ratio of the tiled area to the untiled area tells us nothing at all about the possible lengths for the strip. It's like a Data Sufficiency statement that is automatically insufficient: given a ratio, you don't know anything about actual numbers. With that in mind, any of the three numbers could be the width of the strip, so the correct answer is (E).

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