If positive integer x is a multiple of 6 and positive integer y is a multiple of 14, is xy a multiple of 105?
(1) x is a multiple of 9
(2) y is a multiple of 25
(1) x is a multiple of 9
(2) y is a multiple of 25
The answer is B.
for xy to be a multiple of 105 (prime factorization of 5,3, 7), xy must have at least one 5, one 3 and one 7.
Only statement 2 tells us that y is a multiple of 5, the prime number we are looking for.
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