NPV question

Micronet Corp. concluded a market research study on a four-year project. The project’s expected NPV is $55,000, its equivalent annual cost is $18,000 and depreciation is $3000 per year. If the firm pays taxes at 40 percent, then its required rate of return is closest to: a) 11.7 b) 13.5 c) 17.8 d) 19.4 The answer is a), based on the PV of the 18K payments (PV=55000, n=4, pmt=18000, i=?). Maybe my brain is fried, but I’m a bit confused as to why the calculation would be based on COSTS yielding a positive NPV. My understanding is that the 18K annual costs would lead to a negative PV, but the NPV is 55,000. Can someone clarify? Thanks,632363,632393#msg-632393