Question

DJ Davon is making a playlist for work; he is trying to decide what 12 songs to play and in what order they should be played. If he has his choices narrowed down to 14 blues, 25 country, and 21 disco songs, and he wants to play an equal number of blues, country, and disco songs, how many different playlists are possible

Answer 1

3.63 * 10^19

Explanation:

Given that :

Number of choices to select = 12

Category available :

Blues - 14

Country - 25

Disco - 21

To select an equal number of song for each category ; then 4 songs will be selected from each :

Using combination :

(14C4 * 25C4 * 21C4)

Since the order matters for the 12 selected songs ; it thus requires 12 permutation

Thus ;

(14C4 * 25C4 * 21C4) * 12!

nCr = n! / (n-r)!r!

Using calculator;

14C4 = 1001 ;

25C4 = 12650

21C4 = 5985

12! = 479001600

Hence,

(1001 * 12650 * 5985) * 479001600

= 36301596217286400000

=3.63 * 10^19