13.2 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 distinct objects?

Back

The number of permutations of n distinct objects is calculated using the formula n! (n factorial), which is the product of all positive integers up to n.

Front

What is the value of 5! (5 factorial)?

Back

5! = 5 × 4 × 3 × 2 × 1 = 120.

Front

How many ways can you arrange 3 books out of 5?

Back

The number of ways to arrange 3 books out of 5 is calculated as 5P3 = 5! / (5-3)! = 60.

Front

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

Back

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

Front

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

Back

You can arrange 4 different letters in 4! = 24 ways.

Front

How many ways can you arrange 2 letters from the word 'SQUARE'?

Back

You can arrange 2 letters from 'SQUARE' in 6P2 = 30 ways.

Front

What is the difference between permutations and combinations?

Back

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

Front

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

Back

There are 5P3 = 60 ways to select a president, vice president, and secretary.

Front

How many different 3-digit PINs can be created using digits 0-9 without repetition?

Back

You can create 720 different 3-digit PINs using digits 0-9 without repetition.