An environmental engineer wants to evaluate three different methods for disposing of a non-hazardous chemical waste: land application, fluidized-bed incineration, and private disposal contract. Use the estimates below to help him determine which has the least cost at i = 10% per year, on the basis of an (a) annual worth, and (b) present worth evaluation. Land Incineration Contract First cost, S-150,000 -900,000 0 AOC, S/year-95,000 -60,000 -140,000 Salvage value, $ 25,000 300,000 0 Life, years 4 6 2