Final answer:
Damon started with 95 songs.
Step-by-step explanation:
To find out how many songs Damon started with, we need to subtract the total number of new songs he purchased from the total number of songs across all playlists.
Since there are 4 playlists and each playlist contains 20 songs, the total number of songs across all playlists is 4 * 20 = 80 songs.
If Damon added 15 new songs, then the number of songs he started with is 80 + 15 = 95 songs.