Question: COURSE ENROLLMENTS Among 500 freshmen pursuing a business degree at a university, 320 are enrolled in an economics course, 225 are enrolled in a mathematics course, and 140 are enrolled in both an economics and a mathematics course. What is the probability that a freshman selected at random from this group is enrolled in
a. An economics and/or a mathematics course?
b. Exactly one of these two courses?
c. Neither an economics course nor a mathematics course?