Data Sufficiency

25. 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,

I thought the answer would be C), 2,3 would be consecutive prime numbers.... but the answer turned out to be B) -- Can anyone please explain why only 2) is sufficient?

dunkin77 wrote:25. 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,

I thought the answer would be C), 2,3 would be consecutive prime numbers.... but the answer turned out to be B) -- Can anyone please explain why only 2) is sufficient?

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The answer would be B. (1) tells us that m is a prime number. We do not know anything about n.

(2) tells us that m and n are consecutive integers. The greatest common divisor can be only the value of 1.