Question

Find the number of ways to listen to four CDs from a selection of 8 CDs. A) 1680 B) 336 C) 70 D) 50 pls aslo explain why..

Answer 1

a) 1680

The number of ways to listen to four CDs from a selection of 8 CDs = 1680

Explanation:

Explanation:-

Given data the number of CD' s n = 8

We have to selected '4' CD' s from total '8' CD's

By using permutations

The number of ways to listen to four CDs from a selection of 8 CDs.

=
`8_{P_(4) }`

we know that

`n_{P_(r) } = (n!)/((n-r)!)`

`8_{P_(4) } = (8!)/((8-4)!) = (8 X 7 X 6 x 5 X 4!)/(4!) = 1680`

The number of ways to listen to four CDs from a selection of 8 CDs = 1680