A company bought a new machine for $300,000. The new machine generated revenue for $90,000 per year. Operating cost of that machine is $10,000 per year. The machine is depreciated according to 7-years MACRS method. The machine is sold for $80,000 in the middle of 6 th year of service. Determine the after tax net present worth. Assume, the after-tax MARR is 10% and income tax rate is 25% (federal and state combined).