Question

The probability that a student takes a history class and sociology class is 0.051. The probability that a student takes a history class is 0.32. What is the probability that a student takes a sociology class given that the student is taking a history class

Answer 1

let the event student takes history , call this event H
the event student takes sociology S.
we want
P(S | H ) = P ( S & H ) / P(H)

Answer 2

P(S|H) means probability of S given H has occured