please solve without excel and show calculations thanks!

3) The Reading Railroad is considering a $100,000 investment in either of two companies. Both projects are expected to have a 10-year life. The annual cash flows for the following 10 years are as follows: Year Electric Co Water Works 1 $70,000 $15,000 2 $15,000 $15,000 3 $15,000 $70,000 4-10 $10,000 $10,000 a) Using the payback method, what decision should be made if the firm requires a payback of 4 years for all projects. Show your work. (5 Marks) b) Explain why the answer in part a can be misleading. (2 Marks) c) Calculate the NPV of the Electric Co investment given that Reading Railroad has a cost of capital = 8% (4 Marks) d) Using a financial calculator or excel, calculate the IRR of the Electric Co investment. (2 Marks)