Compare the following machines on the basis of their present worth. Use 12% per year. Machine A Machine B First cost 44,000 23,0000 Annual operating cost 7,000 9,000 Annual repair cost 210 350 Overhaul every 2 years 1,900 Overhaul every 5 years 2,500 Salvage value 4,000 3,000 Life, years 14 7