1. A machine was bought 10 years ago for 30,000 it could be sold today for 10,000 next year for 8,000 in two years for 5,000 and in 3 years for 3,000. The maintenance costs will be 25,000 in year 1, 3,000 in year 2 and 5,000 in year 3 What are the marginal costs of the machine during the first three years after the interest rate is 10%
2. a company buys a machine for $ 10,000 with a life of 5 years, with no salvage value and no annual costs, no salvage value and no annual maintenance costs the depreciable machine with the straight-line method generates profits of 3,000 in the first year and remain constant in purchasing power for the rest of the life of the project. The company pays contributions at 40% and the interest rate is 5% suppose that it can make alternative investments that yield 8% in current dollars, which is the present value of the cash flow for the second year net of contributions.

Please dont use excel if possible and state around how much time these problems took you, Thank you