Lesson 4

As with permutations, there are often extra conditions placed on the choices to be made. For instance, in question 2 of Self-Check 2, the basketball coach could create a line-up comprised of any 15 players. But not all players can play all positions. It’s unlikely that a centre would play guard, for example. If the coach had to make choices based on positions, then the number of combinations would change. Consider the following scenario.

Try This 3

A hockey coach wishes to choose her first line. She has 5 centres from which she must choose one, 7 right-wingers from which she must choose one, 6 left-wingers from which she must choose one, and 10 defensemen from which she must choose two. In how many ways can the coach choose her first line?

Use a table similar to the following to help solve the problem.

Save your answers to your course folder.