Question

A store had 235 MP3 players in the month of January. Every month, 30% of the MP3 players were sold and 50 new MP3 players were stocked in the store.
Which recursive function best represents the number of MP3 players in the store f(n) after n months?

Answer 1

We let f(0) = 235
After 1 month,
f(1) = 235*(0.7) + 50
After 2 months,
f(2) = 235*0.7*0.7+ 50*2
And so on..

Therefore, we can represent the number of MP3 players in the store after n months with the function:
f(n) = 235 (0.7)^n + 50n