Final answer:
The percent of change from 15 to 105 songs is a 600% increase.
Step-by-step explanation:
To find the percent of change, we need to determine the difference between the starting value and the ending value, and then divide that difference by the original value. In this case, the difference is 105 - 15 = 90 songs. Divide that by 15 to get 90/15 = 6. Multiplying by 100 gives us a percent change of 600%. Since the number of songs increased from 15 to 105, the percent of change is a 600% increase.