please help with all three of these!! i am struggling and i dont know if those anwers are correct

thank you

Problem 5-2 Calculating Payback An investment project provides cash inflows of $690 per year for eight years. a. What is the project payback period if the initial cost is $1,475 ? (Enter 0 if the project never pays back. Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) b. What is the project payback period if the initial cost is $3,500 ? (Enter 0 if the project never pays back. Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) c. What is the project payback period if the initial cost is $5,700 ? (Enter 0 if the project never pays back. Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.)