In a small lottery, there is a certain number of tickets. 20% of the tickets are winnings. You want to buy 3 tickets and think about how likely it is that at least one of them will be a winning ticket. This, of course, depends on how many tickets there are in the lottery.
a) If there are 10 tickets in the lottery, what is the probability that at least one ticket is a winning ticket if you buy 3 tickets?
b) If there are 1000 tickets in the lottery, what is the probability that at least one ticket is a winning ticket if you buy 3 tickets?