Could you please help me answer this finance problem? I am not sure how to use excel to answer these kinds of question but my teacher requires it. Thank you in advance!

5.12 Problems with Profitability Index The Cori's Sausage Corporation is trying to choose between the following two 1 mutuallv exclusive design proiects: a. If the required return is 10 percent and the company applies the profitability index decision rule, which project should the firm accept? b. If the company applies the NPV decision rule, which project should it take? c. Explain why your answers in (a) and (b) are different