VJesus12 wrote:Is x > 0?
(1) x² > 0
(2) x + 2 > 0
Target question: Is x > 0?
Statement 1: x² > 0
This statement doesn't feel sufficient, so I'll TEST some values.
There are several values of x that satisfy statement 1. Here are two:
Case a: x = 1. In this case, the answer to the target question is
YES, it is the case that x > 0
Case b: x = -1. In this case, the answer to the target question is
NO, it is NOT the case that x > 0
Since we cannot answer the
target question with certainty, statement 1 is NOT SUFFICIENT
Statement 2: x + 2 > 0
There are several values of x that satisfy statement 2. Here are two:
Case a: x = 1. In this case, the answer to the target question is
YES, it is the case that x > 0
Case b: x = -1. In this case, the answer to the target question is
NO, it is NOT the case that x > 0
Since we cannot answer the
target question with certainty, statement 2 is NOT SUFFICIENT
Statements 1 and 2 combined
IMPORTANT: Notice that I was able to use the
same counter-examples to show that each statement ALONE is not sufficient.
So, the same counter-examples will satisfy the two statements COMBINED.
In other words,
Case a: x = 1. In this case, the answer to the target question is
YES, it is the case that x > 0
Case b: x = -1. In this case, the answer to the target question is
NO, it is NOT the case that x > 0
Since we cannot answer the
target question with certainty, the combined statements are NOT SUFFICIENT
Answer: E
Cheers,
Brent
