A biogas plant has a five-year-old equipment that was initially purchased for $80,000. The equipment can be kept in service for an additional five years, or it can be sold for $45,000 and replaced by a new equipment. The purchase price of the replacement equipment is $65,000. The projected MVs and operating and maintenance costs over the five year planning horizon are shown in the table that follows. Assuming the MARR is 8%, a-) determine the economic life of the challenger b-) determine when the defender should be replaced. c- Assume that the minimum EUAC of the challenger was $37,000. When the defender should be replaced