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 with 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 resale values are shown in the table below. Challenger Defender MV $42,500 $31,000 $10,000 $17,000 $14,000 $25,000 $12,500 Year O&M costs MV O&M costs 0 $25,000 2 If the before-tax MARR is 15%, when should the old assembly machine be replaced