Hi could someone please help and possibly explain the answer.

How can you find the conditional probability of a given b as the fraction of b’s outcomes that also belong to a, and interpret the answer in terms of the model? i just need a good explanation

What is the remainder when 2872 is divided by 76? a) 51 b) 57 c) 60 d) 63

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b