Permutations & Combinations

Front

What is a permutation?

Back

A permutation is an arrangement of objects in a specific order. The order of arrangement 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 the number of permutations of n objects taken r at a time?

Back

The formula is n! / (n - r)!, where n is the total number of objects and r is the number of objects to arrange.

Front

What does 5! (5 factorial) equal?

Back

5! = 5 × 4 × 3 × 2 × 1 = 120.

Front

What does 0! equal?

Back

0! = 1 by definition.

Front

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

Back

If you have 3 books, the number of arrangements is 3! = 6.

Front

What is the difference between permutations and combinations?

Back

Permutations consider the order of selection, while combinations do not.

Front

How many ways can a club select a president, vice president, and a secretary from a group of 5 people?

Back

60 ways.

Front

What does 10P5 represent?

Back

10P5 represents the number of permutations of 10 choices taken 5 at a time.

Front

What is the value of 8! (8 factorial)?

Back

8! = 40320.