Mr. Garcia sold his machine for P20,000 after using it for 6 years. He bought a new machine worth 75,000 with an expected life of 12 years and a salvage value of 2,000. The operating cost is P5,500 per year. The old machine which he bought for P50,000 when new will be useful for 10 years and a junk value of 1,000 but because of appropriate maintenance, it will be useful for another 5 years, no salvage value, with an annual operating cost of twice the new one. If money is worth 12%, was the engineer justified in selling the old machine? Use the ROR method. Thank you! Please provide a detailed solution.