The task is to generate the correct answer for a given math problem.

[Q]: Problem: if p represents the product of the first 16 positive integers , then p is not a multiple of
[A]: 5

[Q]: Problem: the number of positive integer solutions for the equation x + y + z + t = 30 is
[A]: 3654

[Q]: Problem: if the cost price of 50 articles is equal to the selling price of 40 articles , then the gain or loss percent is ?
[A]:
25 %