Question

From a list of 10 songs, a DJ has to play either 2 or 3 songs. What is the total number of song sequences that he can create?

Answer 1

The total number that he can create is 810

Step-by-step explanation:

two-song lists, 10 choices for the first song, and then 9 remaining choices for the second song. This means

# of two-song playlists = 10*9 = 90

For three-song lists, 10 choices for the first song, then 9 remaining choices for the second song, then 8 remaining choices for the third song. This means

three-song playlists = 10*9*8 = 10*72 = 720

Add those

total number of playlists = 720 + 90 = 810