(1) Nothing has been said about p, so p may or may not be > 0; NOT sufficient.gmatpup wrote:If n and p are integers, is p>0?
A. n+1 > 0
B. np > 0
Answer is C
Please explain! Thanks so much
(2) np > 0
If n = -1, p = -1, then np = 1 > 0; here p < 0
If n = 1, p = 1, then np = 1 > 0; here p > 0
No definite answer; NOT sufficient.
Combining (1) and (2), n > -1 and np > 0
Since n is an integer n cannot be 0 since np > 0 so n has to be positive. If n is positive p has to be positive as np > 0; SUFFICIENT.
The correct answer is C.
