2.A company that makes clutch disks for race cars has the cash flows shown for one department Year Cash Flow, $1000 0 -65 30 84 10 -12 (a) Determine the number of positive roots to the rate of return relation. (b) Calculate the internal rate of return. (c) Calculate the external rate of return using the return on invested capital (ROIC) approach with an investment rate of 15% per year. (d) determine the external rate of return using the modified rate of return approach(MIRR). Assume the company's MARR is 15% per year and its cost of capital is 9% per year