For Nos. 51-60. A mail-order firm wants to install an automatic mailing system to handle product announcement and invoices for the next 10 years. The firm has a choice between 3 different types of systems. The monetary information about the systems is given in the table below: (MARR = 20%): Machines B C Investment Cost $ 50,000 $ 100,000 $ 80,000 Useful Life (years) 10 15 12 Yearly Maintenance Expense Required $ 15,000 $ 3,000 $ 9,000 Depreciation Straight Line SYD Declining Balance Method Salvage Value $8,000 $16,000 $ 21,000