y. If a pumping system has an increasing annual maintenance cost (an arithmetic gradient) of $1,200 per year over an 8-year period, then what is the present value based on 18% interest? (5%) 10. If a pumping system has an increasing annual maintenance cost of S1,200 per year over an 8-year period THAT STARTS AT YEAR 4, then what is the present value based on 18% interest? To be clear the total period is 12 years with an 8-year gradient starting in year 4. (5%)