FCP, Permutations and Combinations Unit Review

Front

What is a permutation?

Back

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

Front

What is a combination?

Back

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

Front

When would you use permutations instead of combinations?

Back

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

Front

When would you use combinations instead of permutations?

Back

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

Front

How many ways can you arrange 3 books on a shelf?

Back

6 ways (3! = 3 x 2 x 1 = 6).

Front

How many ways can you choose 2 fruits from a selection of 5?

Back

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

Front

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

Back

P(n, r) = n! / (n - r)!.

Front

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

Back

C(n, r) = n! / (r!(n - r)!).

Front

If you have 5 different shirts and want to wear 2, how many different outfits can you create?

Back

10 outfits (5 choose 2 = 10).

Front

If you have 10 different books and want to arrange 4 on a shelf, how many arrangements can you make?

Back

5040 arrangements (P(10, 4) = 10! / (10 - 4)! = 5040).