If x is greater than 7, is y less than x?

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If x is greater than 7, is y less than x?

(1) y^2> 49
(2) x^2 - y^2 > 0

How will i know the whether the statement is sufficient?

OA B

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by Jay@ManhattanReview » Thu Nov 09, 2017 9:56 pm
lheiannie07 wrote:If x is greater than 7, is y less than x?

(1) y^2> 49
(2) x^2 - y^2 > 0

How will i know the whether the statement is sufficient?

OA B
(1) y^2 > 49

Case 1: Say y = 9, and x = 8, then the answer is No.
Case 2: Say y = -9, and x = 8, then the answer is Yes. Insufficient.

(2) x^2 - y^2 > 0

=> x^2 > y^2

Case 1: If x = 8, and x = 7, then the answer is Yes.
Case 2: We cannot assume a negative value for x such that its magnitude is greater than that of y since x is a positive number. Thus, x > y. The answer is Yes. Sufficient.

The correct answer: B

Hope this helps!

-Jay
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