Please show work and explain how you got the answer

7-15. You have 3 projects with the following cash flows: Year 0 2 3 -150 20 40 60 80 Project 1 Project 2 -825 0 7000 -6500 80 -245 a. Project 3 20 40 60 For which of these projects is the IRR rule reliable? b. Estimate the IRR for each project to the nearest 1%). c. What is the NPV of each project if the cost of capital is 5%? 20%? 50%