Honors- GC Permutations and Combinations

Front

What is a permutation?

Back

A permutation is an arrangement of objects in a specific order. The order matters in permutations.

Front

What is a combination?

Back

A combination is a selection of objects where the order does not matter. Only the group of objects is important.

Front

When do you use permutations?

Back

Use permutations when the arrangement or order of the selected items is important.

Front

When do you use combinations?

Back

Use combinations when the arrangement or order of the selected items is not important.

Front

How many ways can you arrange 4 books on a shelf?

Back

24 ways (4! = 4 x 3 x 2 x 1 = 24).

Front

How many ways can you choose 3 students from a group of 10?

Back

120 ways (10 choose 3 = 10! / (3! * (10-3)!) = 120).

Front

What is the formula for permutations of n items taken r at a time?

Back

The formula is P(n, r) = n! / (n - r)!.

Front

What is the formula for combinations of n items taken r at a time?

Back

The formula is C(n, r) = n! / (r! * (n - r)!).

Front

If you have 5 different shirts, how many ways can you choose 2 shirts?

Back

10 ways (5 choose 2 = 5! / (2! * (5-2)!) = 10).

Front

If you have 8 players and need to choose a captain and co-captain, is this a permutation or combination?

Back

This is a permutation because the order (captain vs co-captain) matters.