Answer:
a) There are 300 ways to pick two students so that one is in the CS major and the other is in the Math major.
b) 35 ways that one representative can be picked who is either a CS major or a Math major.
Step-by-step explanation:
a. If no student is in both majors, how many ways are there to pick two students so that one is in the CS major and the other is in the Math major?
The ordering is not important, so there are 20*15 = 300 ways to pick two students so that one is in the CS major and the other is in the Math major.
b) In how many ways can one representative be picked who is either a CS major or a Math major?
Since no student is in both majors, there are 20+15 = 35 ways that one representative can be picked who is either a CS major or a Math major.
