It costs $30,000 to retrofit the gasoline pumps at a certain filling station so the pumps can dispense E85 fuel. if the station makes a profit of $0.08 per gallon from selling E85 and sells an average of 20,000 gallons of E85 per month, how many months will it take for the owner to recoup her 30,000 investment in the retrofitted pumps? the interest rate is 1% per month. How would you do this with an interest chart and a calculator.