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? f(n) = 0.7 x f(n − 1) + 50, f(0) = 235, n > 0 f(n) = 237 − 0.7 x f(n − 1) + 50, f(0) = 235, n > 0 f(n) = 0.3 x f(n − 1) + 50, f(0) = 235, n > 0 f(n) = 237 + 0.7 x f(n − 1) + 50, f(0) = 235, n > 0
Accepted Solution
A:
Answer is A) f(n) = 0.7 x f(n − 1) + 50, f(0) = 235, n > 0
This demonstrates the 30% decrease in the stock by multiplying the previous month's number by .7, and also adds 50 mp3 players each month. Plugging in the first month: f(1) = .7 * 235 + 50 f(1) = 165 + 50 = 215 This is consistent with a 30% decrease in the stock, plus 50.