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Question? If x and y are positive integers, is 2x/y an integer?1. All factors of y are also factors of x?2. All prime factors of y are also prime factors of xThe answer is A. I understand why the first part is sufficient, but I can't seem to pick numbers that would make the second part insuffcient. Can someone explain this?Thanks

x=3, y=9. The only prime factor of y is 3, which divides x, but 2(3)/9 = 2/3 is not an integer.Basically powers of primes are problematic. Having higher powers of primes in the factorization does not change the prime factors. The first case scenario takes care of this because it takes into account all factors, including powers of primes.