What is the greatest common divisor of positive integers m and n?

(1) m is a prime number.

(2) m and n are consecutive integers.

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:

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Using the rule that any two consecutive are co- primes we can say B is sufficient and GCD =1
hence B
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