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

Q: Problem: robert ' s salary was decreased by 20 % and subsequently increased by 20 % . how much percentage does he lose ?

A: 4 %
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Q: Problem: how many quarters are equal to 7 dollars ?

A: 28
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Q: Problem: in n is a positive integer less than 200 , and 2 n / 108 is an integer , then n has how many different positive prime factors ?

A:
3
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