Please answer without using excel spreadsheet.

You have 3 projects with the following cash flows: Year 0 1 2 3 Project 1 - $152 $22 $42 $59 Project 2 - 825 0 0 6,990 Project 3 22 41 58 79 a. 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%? 4 $78 -6,493 - 246