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

[Q]: Problem: a circular ground whose diameter is 70 metres , has a 2.8 metre - broad garden around it . what is the area of the garden in square metres ?
[A]: 640.64


[Q]: Problem: by selling an article for $ 195 , a person gains $ 45 . what is the gain % ?
[A]: 30 %


[Q]: Problem: in n is a positive integer less than 200 , and 14 n / 60 is an integer , then n has how many different positive prime factors s ?
[A]:
3