Is x less than 20?

[BTGmoderatorDC]

Is x less than 20?

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




OA E

Source: e-GMAT

[Brent@GMATPrepNow]

Is x less than 20?

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

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

Cheers,
Brent