help pls

Red Bull is considering to two mutually exclusive marketing projects. Each requires an initial investment of $100.000. The president of the company has set a maximum payback period of 4 years. The CFs are as follows: 1.- Determine the payback period of each project. 2.- Calculate the NPV of each project considering a 10% of cost of opportunity. 3.- Determine which project you'd recommend to invest in. 4.- Calculate the PI, does your decision change