Is x less than 20?

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Re: Is x less than 20?

by Brent@GMATPrepNow » Sun Oct 11, 2020 5:09 am

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BTGModeratorVI wrote: ↑
Wed Oct 07, 2020 7:22 am
Is x less than 20?

(1) The sum of x and y is less than 20.
(2) y is less than 20.

Answer: e
Source: official guide

Target question: Is x less than 20?

When I scan the two statements, I can quickly see that neither statement alone is sufficient.
So let's jump straight to....
.
.
.

Statements 1 and 2 combined
There are several values of x and y that satisfy BOTH statements. Here are two:
Case a: x = 5 and y = 5. In this case, the answer to the target question is YES, x is less than 20
Case b: x = 30 and y = -30. In this case, the answer to the target question is NO, x is not less than 20
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer: E

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Brent

Brent Hanneson - Creator of GMATPrepNow.com