I need this question answered showing all of the word including all formulas and equations. I don't need an excel file showing the answers.

1. Whole Foods is evaluating two mutually exclusive investment projects as shown below: Time Project Cooper Project Delta 0 1 2 3 4 -$20,000 5,000 8,000 10,250 20,000 $20,000 16,500 10,000 5,000 5,000 1a. If the cost of capital is 15%, which project would you prefer based only on NPV? Why? (20 points) 1b. If you are evaluating the project based on profitability index, which project would you prefer? Assume the cost of capital is 15%. (10 points) 1c. Compute the payback (non discounted) period for both projects. (10 points) Note: You have to show all your work, including the formula, to get full credit. A simple answer will not get any credit at all