An investment project has annual cash inflows of $5,100, $3,200, $4,400, and $3,600, for the next four years, respectively. The discount rate is 15 percent.

a. What is the discounted payback period for these cash flows if the initial cost is $5,000?

b. What is the discounted payback period for these cash flows if the initial cost is $7,100?

c. What is the discounted payback period for these cash flows if the initial cost is $10,100?