An investment project has annual cash inflows of $3,300,$4,200,$5,400, and $4,600. 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 $6,000 ? (Do not round intermediate calculations and round your onswer to 2 decimal places, e.g., 32.16.) b. What is the discounted payback period for these cash flows if the initial cost is $8,100 ? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) c. What is the discounted payback period for these cash flows if the initial cost is $11.100 ? (Do not round intermediote calculations and round your answer to 2 decimal places, e.g., 32.16.)