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If a positive factor of n is chosen at random, what is the probability that the chosen factor is an odd number?

At first I thought of listing out the factors like you would for 1×2×3×4×5 for example. Which is in this case {1,2,3,6,8,10,12,15,20,40,60,120} but it is way too many factors for n=25! as the number is huge.

Then maybe I thought of using modular concept but I'm really not familiar with it at all. I can't really spot any pattern either. So I really need someone to help me. Thanks!