Potable water is in short supply in many countries. To address this need, two mutually exclusive water purification systems are being considered for implementation in China. Doing nothing is not an option. Assume the repeatability of cash flows for alternative 1. a. Use the PW method to determine which system should be selected when MARR = 7% per year. b. Which system should be selected when MARR = 18% per year? System 1 System 2 Capital investment $100,000 $150,000 Annual revenues 55,000 65,000 Annual expenses 22,000 40,000 MV at end of useful life 20,000 0 Useful life 5 years 10 years IRR 22.8% 10.6%