Please I really need help with this

Question

A student goes to the library. The probability that she checks out a fiction book is 0.45, a work of non-fiction book is 0.28, and both fiction and non-fiction book is 0.10. What is the probability that the student checks out a fiction of non-fiction book?

Answer 1

The probability of either of 2 events happening is the sum of each probability. So, P being probability, P(Event A OR Event B) = P(Event A) + P(Event B). P(Checking out a fiction book OR Checking out a non-fiction book) = ...