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.

Saludos desde Mexico.

Hi aznmexicana,

The key to this question, as to many DS questions, is accurate rephrasing. We know that xy is a multiple of 6*14, or of 2^2*3*7. We want to know whether xy is a multiple of 105, or of 3*5*7. Since we already know that xy is a multiple of 3*7, the rephrase is: "Is xy a multiple of 5?" Statement (2) gives us enough data to answer but statement (1) doesn't, so the answer is B

Attached is a more detailed solution and take-away strategies. If you cannot see the attachment, get it here

Good luck,
-Patrick

thanks patrick!! that was really helpful!