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

Answer:

a) 1680

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

Step-by-step 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

           $n_{P_{r} } = \frac{n!}{(n-r)!}$

          $8_{P_{4} } = \frac{8!}{(8-4)!} = \frac{8 X 7 X 6 x 5 X 4!}{4!} = 1680$

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