Identifying Combination vs. Permutation

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 a combination instead of a permutation?

Back

Use a combination when the order of selection is not important, such as choosing toppings for a sundae.

Front

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

Back

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

Front

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

Back

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

Front

If you have 5 books and want to arrange them on a shelf, what is this an example of?

Back

This is an example of a permutation.

Front

If you have 10 different fruits and want to choose 3 to make a fruit salad, what is this an example of?

Back

This is an example of a combination.

Front

What does 'n' represent in the context of combinations and permutations?

Back

In combinations and permutations, 'n' represents the total number of items to choose from.

Front

What does 'r' represent in the context of combinations and permutations?

Back

In combinations and permutations, 'r' represents the number of items to be chosen.

Front

How many ways can you choose 2 toppings from a list of 5?

Back

Using combinations, C(5, 2) = 10 ways.