required rate of return

Project K has a cost of $52,125, and its expected net cash inflows are $12,000 per year for eight years.
a. What is the project's payback period (to the closest year)?
b. The required rate of return for the project is 12 percent What is the project's NPV?
c. What is the project's IRR?
d. What is the project's discounted payback period, assuming a 12 percent required rate of return?