gmat25 wrote: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
As x is a multiple of 6 (= 2*3) and y is a multiple of 14 (= 2*7), xy is a multiple of 6*14 = 84. Hence, xy is a multiple of 3, 4, and 7. Now for xy to be a multiple of 105 (= 3*5*7), xy has to be a multiple of 5 also.
Only statement 2 allows us to conclude that xy is a multiple of 5 too as y is a multiple of 25.
The correct answer is B.
