Hi All,
We're told that X is an integer. We're asked if X is divisible by 36. This is a YES/NO question and can be solved by TESTing VALUES.
1) X is divisible by 12.
IF....
X = 12, then the answer to the question is NO.
X = 36, then the answer to the question is YES.
Fact 1 is INSUFFICIENT
2) X is divisible by 9.
IF....
X = 9, then the answer to the question is NO.
X = 36, then the answer to the question is YES.
Fact 2 is INSUFFICIENT
Combined, we know...
X is divisible by 12
X is divisible by 9
Here, the 'overlap' isn't too difficult to define. X could be... 0, 36, 72, 108, 144, etc. In ALL cases, X is divisible by 36. Thus, the answer to the question is ALWAYS YES.
Combined, SUFFICIENT
Final Answer: C
GMAT assassins aren't born, they're made,
Rich