Is \(x > y ?\)

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Source: — Data Sufficiency |

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by Brent@GMATPrepNow » Sat Dec 14, 2019 5:58 am
M7MBA wrote:Is \(x > y ?\)

(1) \(x + y < 0\)
(2) \(x - y > 0\)
Target question: Is x > y?

Statement 1: x + y < 0
Let's TEST some values.
There are several values of x and y that satisfy statement 1. Here are two:
Case a: x = 1 and y = -2 (this satisfies the condition that x + y < 0). In this case, the answer to the target question is YES, x IS greater than y
Case b: x = -2 and y = 1 (this satisfies the condition that x + y < 0). In this case, the answer to the target question is NO, x is NOT greater than y
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: x - y > 0
When we add y to both sides of the inequality, we get x > y
Perfect!
The answer to the target question is YES, x IS greater than y
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: B

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Brent
Brent Hanneson - Creator of GMATPrepNow.com
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