Hi All,
Even though this is an old post (and most of the original posters are probably long gone), this question serves as a nice example of some of the Number Properties that you're likely to face on Test Day. If you can spot the NPs involved, then you can move relatively quickly through the work, but even if you don't recognize the NPs, you can still TEST VALUES to prove that patterns exist. In that way, you can do some quick work and avoid "staring at the screen" and hoping that something comes to you.
We're told that M and N are INTEGERS. We're asked if M is ODD. This is a YES/NO question.
Fact 1: N + M is ODD
IF....
N = 1
M = 0
The answer to the question is NO
IF....
N = 0
M = 1
The answer to the question is YES
Fact 1 is INSUFFICIENT
Fact 2: N + M = N^2 + 5
Here, the value of M depends on the value of N. Let's start with something simple and see if a pattern emerges.
IF....
N = 0
M = 5
The answer to the question is YES
IF....
N = 1
M = 5
The answer to the question is YES
IF....
N = 2
M = 7
The answer to the question is YES
IF....
N = 3
M = 11
The answer to the question is YES
It certainly looks like the answer to the question is ALWAYS YES. We can quickly TEST some negative values for N and see what happens....
IF....
N = -1
M = 7
The answer to the question is YES
IF....
N = -2
M = 11
The answer to the question is YES
Fact 2 is SUFFICIENT
Final Answer:
GMAT assassins aren't born, they're made,
Rich