(If necessary, consult a list of formulas.) (a) A certain committee consists of 15 people. From the committee, a president, a vice-president, a secretary, and a treasurer are to be chosen. In how many ways can these 4 offices be filled? Assume that a committee member can hold at most one of these offices. (b) A company that makes crayons is trying to decide which 4 colors to include in a promotional mini-box of 4 crayons. The company can choose the 4 mini-box colors from its collection of 65 colors. How many mini-boxes are possible?