VJesus12 wrote:If -10 < k < 10, is k > 0?

(1) 1/k > 0
(2) k² > 0

Target question: Is k > 0

Given: -10 < k < 10

Statement 1: 1/k > 0
In other words, 1/k is POSITIVE
Since 1 is positive, we can write: POSITIVE/k = POSITIVE
From this, we can conclude that k must be POSITIVE
So, the answer to the target question is YES, it is the case that k > 0
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: k² > 0
There are several values of k that satisfy statement 2. Here are two:
Case a: k = 1. In this case, the answer to the target question is YES, it IS the case that k > 0
Case b: k = -1. In this case, the answer to the target question is NO, it is NOT the case that k > 0
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Answer: A

Cheers,
Brent