A travelling salesman is attempting to convince me to invest in a gokart building project. This project should produce $10,000 positive cash flows for the next 5 years, after which I will receive nothing. The saleman wants requires a $30,000 investment for me to get the future cash flows. If I can normally get 8% return on my investments, AND the salesman is accurate with his cash flow predictions, what is the payback period in years if I accept his offer?