Is x less than y?

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by Brent@GMATPrepNow » Tue Dec 17, 2019 7:21 am

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BTGmoderatorDC wrote:Is x less than y?

(1) x - y + 1 < 0
(2) x - y - 1 < 0

Target question: Is x < y?

Statement 1: x-y+1<0
Add y to both sides to get x+1 < y

Big point: x < x+1

When we combine the two inequalities, we get x < x+1 < y
From this, we can definitely see that x < y
So, statement 1 is SUFFICIENT

Statement 2: x-y-1<0
Add y to both sides to get x-1 < y

Big point: x-1 < x

In this instance, we can see that y and x are both greater than x-1
Given this, we cannot tell whether x < y
So, statement 2 is NOT SUFFICIENT

Answer: A

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Brent

Brent Hanneson - Creator of GMATPrepNow.com