Exercise 3.8.18: How many ways are there to choose five cardsfrom 52 so that you have all the aces? How many ways are there tochoose five cards from 52 so that you have four cards with the samenumber?
Exercise 3.8.20: How many ways are there to choose five cardsfrom 52 so that you have two cards with the same number? Hint: Thisproblem is more tricky than you think.