Projects X, Y, and Z involve initial investments of $-5000, $-6000, and $-7000 respectively. Project X yields $2000 per year for 4 years. Project Y gives $2500 per year for 4 years. Project Z returns $3000 per year for 4 years.

a) Calculate the NPV at a 10% discount rate.

b) Determine which project(s) should be accepted based on NPV.

c) Find the payback period for each project.

d) Decide which project(s) to accept with a 3-year payback period cutoff.