please don't solve with excel.

a Question #5 (15 Points): The cash flows associated with a certain project are shown below. Year 0 1 2 3 Costs $ 40,000 20,000 25,000 25,000 Revenues $ 0 52,000 43,000 23,000 4 15,000 13,000 5 10,000 20,000 a) What is the number of possible i* values? Why? b) Determine the external rate of return using the MIRR method if the investment rate is 18% per year and the borrowing rate is 10% per year. Show your steps