I have the operating cash flows figured out but am stuck on the NPV's

Bottoms Up Diaper Service is considering the purchase of a new industrial washer. It can purchase the washer for $4,800 and sell its old washer for $1,200. The new washer will last for 6 years and save $1,400 a year in expenses. The opportunity cost of capital is 18%, and the firm's tax rate is 40%. a. If the firm uses straight-line depreciation to an assumed salvage value of zero over a 6-year life, what is the annual operating cash flow of the project in years 1 to 6? The new washer will in fact have zero salvage value after 6 years, and the old washer is fully depreciated. Annual operating cash flow 1,160 b. What is project NPV? (Negative amount should be indicated by a minus sign. Do not round intermediate calculations. Round your answer to 2 decimal places.) NPV c. What is NPV if the firm uses MACRS depreciation with a 5-year tax life? Use the MACRS depreciation schedule. (Do not round intermediate calculations. Round your answer to 2 decimal places.) NPV