Problem (7): Two manufacturers offered the estimate below: Offer A Offer B First Cost, $ Annual M&O cost, $ per year 17,600 3,350 13,800 3,600 1,400 7 Salvage Value, $ (10% residual value) Life, Years 1,800 10 a. Which Offer should be selected using PW analysis, if MARR is 15%? b. If a 5-year study period is adopted and the residual values are expected to be 20% and 50% of the machine's value, for vendors A and B respectively. Which Offer should be selected? C. A 10-year study period is adopted. For Offer A, the company is considering renting for the remaining of the required study period. What annual rate would make both offers economically equivalent