will you please help me with this question with all parts and thank you

3. (35%) A CNC machine was purchased two years ago for $90,000. At the present time, it can be sold for $45,000 and replaced by a newer model having a purchase price of $90,000; or it can be kept in service for a maximum of two more year. The new CNC 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 below table on a year-by- year basis. The MARR is 10%. a) (20%) Calculate the economic life of challenger and defender. Show all your calculations. b) (10%) When should the old CNC machine be replaced? Justify your answer. c) (5%) If the useful life of the defender and challenger were given differently or the study period was different the useful life of the alternatives, do you still follow the same solution procedure? Explain your answer in detail and if there is any assumption you need to make, please state it as well. Year 0 1 2 Challenger Market Value O&M Costs $90,000 67,000 $20,000 45,000 25,000 Defender Market Value O&M Costs $45,000 28,000 $32,000 5000 46000 3. (35%) A CNC machine was purchased two years ago for $90,000. At the present time, it can be sold for $45,000 and replaced by a newer model having a purchase price of $90,000; or it can be kept in service for a maximum of two more year. The new CNC 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 below table on a year-by- year basis. The MARR is 10%. a) (20%) Calculate the economic life of challenger and defender. Show all your calculations. b) (10%) When should the old CNC machine be replaced? Justify your answer. c) (5%) If the useful life of the defender and challenger were given differently or the study period was different the useful life of the alternatives, do you still follow the same solution procedure? Explain your answer in detail and if there is any assumption you need to make, please state it as well. Year 0 1 2 Challenger Market Value O&M Costs $90,000 67,000 $20,000 45,000 25,000 Defender Market Value O&M Costs $45,000 28,000 $32,000 5000 46000