the answer is in red. please do not use excel to find the solution

12.5 (LG 12.2) A chemical plant is considering installing a new water purification system that costs $21 500. The expected service life of the system is 10 years and the salvage value is computed using the declining balance method with a depreciation rate of 20 percent. The operating and maintenance costs are esti- mated to be $5 per hour of operation. The expected savings are $10 per operat- ing hour a. Find the annual worth of the new water purification system if the current operating hours are 1500 per year, on average. The MARR is 10 percent b. What is the break-even level of operating hours? Construct a graph showing the annual worth for various levels of operating hours. Ans. 671 Ang 4146