An initial investment of $120,000 is made. The net cash flows are as follows:

• Year 1: $15,000
• Year 2: $25,000
• Year 3: $30,000
• Year 4: $35,000
• Year 5: $40,000
• Year 6: $50,000

Requirements:

1. Calculate the cumulative net cash flows for each year.
2. Determine the payback period (in years) for the investment.
3. Compute the Net Present Value (NPV) of the investment if the discount rate is 10%.
4. Calculate the Internal Rate of Return (IRR) for the investment.