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. It focuses on the group rather than the arrangement.

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

Example of a permutation:

Back

Arranging 3 books on a shelf. The order in which they are arranged matters.

Front

Example of a combination:

Back

Choosing 3 toppings for a pizza. The order of toppings does not matter.

Front

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

Back

4! = 24 ways (permutation) because the order matters.

Front

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

Back

10C3 = 120 ways (combination) because the order does not matter.

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)!].