Permutations and Combinations Check for Understanding

Front

What is a combination?

Back

A combination is a selection of items from a larger set where the order does not matter.

Front

What is a permutation?

Back

A permutation is an arrangement of items from a larger set where the order does matter.

Front

How many ways can you choose 5 DVDs from a set of 20?

Back

Using combinations, the number of ways is calculated as 20C5 = 15,504.

Front

How many ways can a coach choose 5 starting players from 11 players?

Back

Using combinations, the number of ways is calculated as 11C5 = 462.

Front

When do you use permutations instead of combinations?

Back

Use permutations when the order of selection matters.

Front

What is the formula for combinations?

Back

The formula for combinations is nCr = n! / (r!(n-r)!), where n is the total number of items and r is the number of items to choose.

Front

What is the formula for permutations?

Back

The formula for permutations is nPr = n! / (n-r)!, where n is the total number of items and r is the number of items to arrange.

Front

If you are selecting a lead and an understudy for a play, is this a permutation or combination?

Back

This is a permutation because the order of selection matters.

Front

What does factorial mean in mathematics?

Back

Factorial, denoted as n!, is the product of all positive integers up to n.

Front

How many different batting orders can a coach create with 10 players?

Back

Using permutations, the number of ways is calculated as 10! = 3,628,800.