Question

A DJ is preparing a playlist of 17 songs. How many different ways can the DJ arrange the first five songs on the​ playlist?

Answer 1

So, first 5 songs-

The first song can be any song from the 17 songs.

The second song can be any song but the song selected before. Thus it can be selected from 16 songs.

Similarly , when we do for the others, the total number of ways the first five songs can be arranged is 17*16*15*14*13=742560 ways.

If you permutations and combinations, we can use permutation here.

17P5 = 17!/(17-5)!=17!/12!=742560.Hope this helps :)