Answer:
5.78Ć10¹āµ
Step-by-step explanation:
The playlist has 12 songs, and he wants the same number of songs for each genre, so he must pick 4 songs per genre.
The number of ways he can choose 4 country songs (ignoring the order) is āāCā = 7315.
The number of ways he can choose 4 reggae songs (ignoring the order) is āāCā = 330.
The number of ways he can choose 4 pop songs (ignoring the order) is ā Cā = 5.
The total number of combinations is 7315 Ć 330 Ć 5 = 1.21Ć10ā·.
Once he has his 12 songs selected, the number of ways he can arrange them is āāPāā = 12! = 4.79Ć10āø.
So the total number of possible playlists is:
(1.21Ć10ā·) Ć (4.79Ć10āø) = 5.78Ć10¹āµ