1. Twenty cookies are to be distributed to ten children. In how many ways can the cookies be distributed if (a) any cookie can be given to any child; (b) If two cookies are to be given to each child?
2. (Bridge Deals). What is the total possible number of deals in a bridge game? A deal is a distribution of 52 cards to four players, each receiving 13 cards.
3. In a building with six floors, an elevator starts with four people at the ground floor. What is the probability that the four people get off at exactly two floors?