Question 298192
Let's assume that the numbers are A & B and it was B that Maurice reverses.

Since B is 2 digits number we can say that B = W + 10 Y

So the exact result would be A * (W + 10 Y) and when he reserves the digits of the B number, the result would be A * (Y + 10 W)

So the difference would be A * (Y + 10 W) - A * (W + 10 Y) = 3015

So A * (Y + 10 W - W -10 Y) = 3015

A * (9 W - 9 Y) = 3015

dividing by 9

A * (W - Y) = 335

335 is the multiplication of 5 * 67 (67 is a prime number)

So the difference between the two digits of the B number is 5

then the correct answer would be (B) 38

In fact we can verify our answer since now we know both numbers A = 67, B = 38

So A * B = 67 * 38 = 2546 and when B is reserved 67 * 83 = 5561 and the difference 5561 - 2546 = 3015 :)