Please, don't use Excel

A machine's initial maintenance costs are covered by a 3-year warranty. Its initial cost is $22000. Salvage value in any year is zero. Assume a 10% interest rate. Compute the economic life with the lowest EUAC. How does the economic life change in an overhaul costing $8800 at the end of year 5 for lives of 6 years or greater? Year Annual Maintenance None 1-3 4-5 $6500 $2500 +$3500/yr 6 7-10