Please help me solve this two part problem. Im struggling.

Thankyou

A high-speed electronic assembly machine was purchased two years ago for $50, 000 At the present time it can be sold for $24,000 and replaced by a newer model having a purchase price of $41, 000; 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. If the before-tax MARK is 12%. when should the old assembly machine be replaced? Use the following data table for your analysis The minimum EUAC value of the challenger is (Round to the nearest dollar) Enter your answer in the answer box and then click Check