A contractor has 10 model home plans to build from and 4 lots on which to build. In how many ways can he choose to arrange these homes assuming he will build a different model on each lot?

In how many ways can a club with 11 members select a president, vice-president, and secretary? [Assume no one person can hold more than one office.]

One question on a history test asks the student to match 5 dates with 5 events. Each date can match only one event. In how many ways can this question be answered?

If there are 16 horses entered in the Belmont Stakes, in how many ways can first, second, and third places be determined?

Determine the number of arrangements for the letters of the given word which has