Official Guide Explanation:
Data Sufficiency #28




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Solution and Metadata

Question: 28
Page: 155
Difficulty: 5 (Moderate)
Category 1: Algebra > Exponents >
Category 2: Arithmetic > Powers and Roots of Numbers > Powers

Explanation: To find the value of ((y)/(x)), you'll need the value of each variable or the ratio between them. Statement (1) is insufficient: it has no information about y. Statement (2) is also insufficient: if x2 = y2, x could equal y, but x could also be -y; for example, if x = 4, x2 = 16, and if y2 = 16, then y could be 4 or -4.

Taken together, the statements are still insufficient. If x = 6, then x2 = 36. If y2 = 36, then y = 6 or y= - 6. Depending on which value of y is correct, the value of ((y)/(x)) could be 1 or -1. Choice (E) is correct.

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