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