A firm purchased some office equipment for a total cost of $300000. The equipment generated net income of $100000 per year. The firm's marginal tax rate is 20%. The equipment was sold at the end of the 4th year for a total of $75000. Assume that MARR is 12%/year. Calculate the net present worth (NPW) of this investment for problems 5-8. 7 (15 points). If the firm used the DDB depreciation, NPW = $23700 $25750 $27440 $29400