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

[EX Q]: Problem: the ratio of the radius of two circles is 1 : 3 , and then the ratio of their areas is ?
[EX A]: 1 : 9

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

[EX Q]: Problem: what is the probability of randomly selecting one of the shortest diagonals from all the diagonals of a regular decagon ( 10 - sided polygon ) ?
[EX A]:
2 / 7