8-2 Permutations

Front

What is a permutation?

Back

A permutation is an arrangement of objects in a specific order. The order of arrangement is important.

Front

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

Back

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

Front

What does the symbol '!' represent in permutations?

Back

'!' represents factorial, which is the product of all positive integers up to that number. For example, 5! = 5 × 4 × 3 × 2 × 1 = 120.

Front

How many ways can you arrange 3 books on a shelf if you have 5 books to choose from?

Back

Using the formula, 5P3 = 5! / (5 - 3)! = 5 × 4 × 3 = 60.

Front

If a club has 5 members, how many ways can they select a president, vice president, and secretary?

Back

60 ways.

Front

How many different ways can you listen to 3 songs from a CD with 12 songs?

Back

1320 ways.

Front

How many ways can you spell the letters of the word 'ILLINOIS'?

Back

3360 ways.

Front

What does the P stand for in nPr?

Back

P stands for Permutations.

Front

How many ways can you choose a King and a First Runner-up from 7 candidates?

Back

42 ways.

Front

What is the difference between permutations and combinations?

Back

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