To get a complete collection of stamps, Ann needs to have 5 specific (and different) kinds of stamps, denoted by k1,…,k5. She starts out with no stamps. She then receives 5 stamps randomly from a lottery. Each of these 5 stamps has probability 1/5 of being of any particular kind ki, and the kinds of the different stamps she receives are independent.

1.What is the probability that Ann has a complete collection after receiving the 5 stamps from the lottery?

2.Given that Ann does not have a complete collection after receiving the 5 stamps from the lottery, what is the probability that she is missing exactly one stamp?