please help!

Two alternatives are being considered for recovering aluminum from garbage. Alternative 1 has a capital cost of $100,000 and a first-year maintenance cost of $12,000, with maintenance increasing by $500 per year for each year after the first. Alterrative 2 has a capital cost of $140,000 and a first-year maintenance cost of $4000, with maintenance increasing by $1000 per year after the first. Revenues from the sale of aluminum are $20,000 in the first year, increasing $2000 per year for each year after the first. The life of both alternatives is 10 years. There is no salvage value. The before-tax MARR is 4\%. Use present worth analysis to determine which alternative is preferred