please include excel formula

Hannah is considering two capital-expenditure projects. Unfortunately, she only has enough money to undertake one of the projects and must therefore choose between the two. The appropriate discount rate for the projects is 12%. The cash flows for both projects occur evenly over the year. The after-tax cash flows for the two projects are as follows: Initial cost Year 1 Year 2 Year 3 Project A (50,000) 30,000 30,000 30,000 Project B (100,000) 55,000 55,000 55,000 Required: a) What is the PBP of each project? Which project is superior based on the PBP method? b) What is the IRR of each project? Which project is superior based on the IRR method? c) Which project should Hannah choose? Explain your reasoning