The coupon collector's problem. Each time one buys a bag of cheese doodles one obtains as a bonus a picture (hidden inside the package) of a soccer player. Suppose there are n different pictures which are equally likely to be inside every package. Find the expected number of packages one has to buy in order to get a complete collection of players. For n = 100 the numerical answer is 519, i.e., "a lot" more than 100.