A presently owned machine can last for three more years, if properly maintained at a cost of $15,000 per year. Its operating cost will be $31,000 per year. After three years, it can be sold for an estimated

$9000. A replacement costs $80,000 with a

$10,000 salvage value after three years and an operating cost of $19,000 per year. Different vendors have offered $10,000 and $20,000, respectively, for the current system in trade for the replacement. At 12% per year interest, perform a replacement study for the two trade-in offers.