An investment project costs $$10,000$ and has annual cash flows of $$2,840$ for six years.

a$.$ What is the discounted payback period if the discount rate is zero percent?

$($Enter $0$ if the project never pays back. Do not round intermediate calculations and round your answer to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$ What is the discounted payback period if the discount rate is $5$ percent?

$($Enter $0$ if the project never pays back. Do not round intermediate calculations and round your answer to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

c$.$ What is the discounted payback period if the discount rate is $20$ percent?

$($Enter $0$ if the project never pays back. Do not round intermediate calculations and round your answer to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$