An machine costs $87,500 with scrap value of $12,000 after 5 years. The asset is expected to increase revenue by $27,000 a year before maintenance costs of $8,200 a year. Assuming a tax rate of 33%, compute the net present value of the investment using a 5% interest rate and depreciation charges obtained from

a. the straight line method of depreciation

b. the sum of years digits method of depreciation

c. the double declining balance method for two years followed by the straight line method.

I need written step by step work, financial calculators and excel are not allowed. Thank you