Hi All,
This DS question can be solved by TESTing VALUES and/or a bit of logic.
We're told that M and N are both POSITIVE INTEGERS. We're asked for the greatest common divisor of M and N.
1) M is a prime number.
This Fact tells us nothing about N.
IF...
M = 2
N = 2
Then the answer to the question is 2
IF...
M = 2
N = 3
Then the answer to the question is 1
Fact 1 is INSUFFICIENT
2) M and N are CONSECUTIVE integers.
The second TEST from Fact 1 'fits' this Fact too...
IF...
M = 2
N = 3
Then the answer to the question is 1
Looking at this example, you might notice that when dealing with consecutive positive integers, the ONLY factor that will divide into both numbers is 1. If you 'TEST' 3 and 4, 4 and 5, 5 and 6, etc., you 'll get the SAME answer every time.
Fact 2 is SUFFICIENT
Final Answer:
GMAT assassins aren't born, they're made,
Rich
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