There are two equal groups of 8 books on the shelf. One group has reading books. In the other group three of the books are math books and the rest are science books. How many science books are there?

Suppose you have six homework assignments to complete one night. (a) In how many different orders can you complete all of the assignments? (b) In how many different orders can you complete all six assignments if you simply must do your statistics assignment first?

If 3 books are picked at random from a shelf containing 5 novels, 3 books of poems, and a dictionary, what is the probability that (a) the dictionary is selected? (b) 2 novels and 1 book of poems are selected?

The call sign for a radio station in the United States is a list of three or four letters, such as WJHU or WJZ. The first letter must be a W or a K, and there is no restriction on the other letters. In how many ways can the call sign of a radio station be formed?

A popular brand of pen is available in three colors (red, green, or blue) and four writing tips (bold, medium, fine, or micro). How many different choices of pens do you have with this brand?

A soccer team has 11 players on the field at the end of a scoreless game. According to league rules, the coach must select 5 of the players and designate an order in which they will take penalty kicks. How many different ways are there for the coach to do this?