A newly opened toll bridge has a life expectancy of 25 years. Considering a rise in construction and other costs, a replacement bridge at the end of that time is expected to cost ` 60,000,000. The bridge is expected to have an average of 100,000 toll-paying vehicles per month for the 25 years.

At the end of every month, the tolls will be deposited into an account bearing annual interest of 11 per cent compounded monthly. The operating and maintenance expenses for the toll bridge are estimated at Re 0.80 per vehicle.

a. How much toll must be collected per vehicle in order to accumulate ` 60,000,000 by the end of 25 years?

b. What should be total toll per vehicle in order to include operating and maintenance cost as well as replacement cost?

c. What annual effective interest rate is being earned?