A high-speed electronic assembly machine was purchased two years ago for $50,000. At the present time, it can be sold for $25,000 and replaced by a newer model having a purchase price of $42,500; or it can be kept in service for a maximum of one more year. The new assembly machine, if purchased, has a useful life of not more than two years. The projected resale values and operating and maintenance costs for the challenger and the defender are shown in the accompanying Table 5(a) on a year-by-year basis. If the before-tax MARR is 15%, solve when should the old assembly machine be replaced? Use the following data Table 5(a) for your analysis. Table 5(a): The projected resale values and operating and maintenance costs Challenger Defender Market O&M Market O&M Year Value Costs Value Costs 0 $42,500 $25,000 1 31,000 $10,000 17,000 $14.000 2 $25,000 12,500