7. The Benson Corporation purchased a machine for $150,000 cash. The useful life of the machine is 10 years, with a salvage value of $40,000. Straight line depreciation using the full-year convention will be used. The machine will generate net income of $30,000 per year for 10 years. Neglect income tax effects, and use the end of year assumption for cash flows. Find the payback period