71. It costs $67,500 to retrofit the gasoline pumps at a certain filling station so the pumps can dispense E85 fuel

(85% ethanol and 15% gasoline). If the station makes a profit of $0.10 per gallon from selling E85 and sells an average of 60,000 gallons of E85 per month, how many months will it take for the owner to recoup her $67,500 investment in the retrofitted pumps? The interest rate is 1% per month. (4.10)