1. Consider lists made from the letters T,H,E,O,R,Y, with repetition allowed.
(a) How many length-4 lists are there?
(b) How many length-4 lists are there that begin with T?
(c) How many length-4 lists are there that do not begin with T?
2. Airports are identified with 3-letter codes. For example, the Richmond, Virginia
airport has the code RIC, and Portland, Oregon has PDX. How many different
3-letter codes are possible?
4. Five cards are dealt off of a standard 52-card deck and lined up in a row. How
many such line-ups are there in which all 5 cards are of the same suit?
6. Five cards are dealt off of a standard 52-card deck and lined up in a row. How
many such line-ups are there in which exactly one of the 5 cards is a queen?