lumone wrote:

If r and s are positive integers, is r/s an integer?

(1) Every factor of s is also a factor of r.

(2) Every prime factor of s is also a prime factor of r.

I think each statement is not sufficient alone

I statement cannot be because suppose

8 and 12, they both have 2 as a factor but 8/12 is not integer

8 and 4, they both have 2 as a factor 8/4 is integer

that is why is not sufficient

II statement

we know that 2 is even prime and examples from first statement can be given there and again it is not sufficient

combined together they give nothing more than alone, so I think it is E