Practice: Permutations and Combinations

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

How do you calculate permutations of n objects taken r at a time?

Back

The formula is n! / (n - r)!.

Front

How do you calculate combinations of n objects taken r at a time?

Back

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

Front

What is the factorial of a number?

Back

The factorial of a number n (denoted as n!) is the product of all positive integers up to n.

Front

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

Back

3! = 6 ways.

Front

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

Back

5C2 = 10 ways.

Front

What is the difference between permutations and combinations?

Back

Permutations consider order; combinations do not.

Front

In how many ways can you select a committee of 3 from 10 people?

Back

10C3 = 120 ways.

Front

If you have 4 different colors, how many ways can you arrange them?

Back

4! = 24 ways.