By the numbers. You are asked to carry out a cost-benefit analysis for a new parking lot. The cost of the parking lot is $3,000,000. Annual maintenance and operating expenses are $60,000. The revenue from users, including the estimated value of "free" parking for city employees, is $200,000 a year, and the parking lot has an estimated useful lifetime of 15 years. At a 5 percent rate of discount, what is the cost-benefit ratio for this project? What other factors might you want to take into account? How would your answer be different if the interest rate was 8 percent?