Question

suppose you choose four books to read from a summer reading list of 12 books. how many different combinations are possible

Answer 1

The number of different combinations that are possible are:

495

Explanation:

The method of combination states that:

If we have to choose r items out of a total of n items then the number of ways of doing so is calculated by the formula:

`n_C_r=(n!)/(r!* (n-r)!)`

Here we are asked to find:

The number of combinations possible when we have to choose 4 books out of 12 books.

i.e. we have: n=12 and r=4

Hence, the number of ways is calculated as follows:

`{12}_C_4=(12!)/(4!* (12-4)!)\\\\\\{12}_C_4=(12!)/(4!* 8!)\\\\\\{12}_C_4=495`