5. (9 points) Each student at some college has a mathematics requirement M (to take at least one mathematics course) and a science requirement S (to take at least one

science course). A poll of 150 sophomore students shows that:60 completed M, 45 completed S, and 25 completed both M and S. Find the number of students who have completed: (a) (3 points) At least one of the two requirements (b) (3 points) Exactly one of the two requirements (c) (3 points) Neither requirement.