3.4 Additional Topics in Probability and Counting

When you calculate the number of permutations of n distinct objects taken r at a​ time, what are you​ counting?

The number of ordered arrangements of n objects taken r at a time.

T/F A combination is an ordered arrangement of objects.

The statement is false. A true statement would be​ "A permutation is an ordered arrangement of​ objects."

T/F The number of different ordered arrangements of n distinct objects is​ n!

True

T/F When you divide the number of permutations of 11 objects taken 3 at a time by​ 3!, you will get the number of combinations of 11 objects taken 3 at a time.

True

When you calculate the number of combinations of r objects taken from a group of n objects what are you​ counting? Give an example

You are counting the number of ways to select r of the n objects without regard to order. An example of a combination is the number of ways a group of teams can be selected for a tournament