Two machines are to be compared with each other, based on their present worth. Machine A has an initial cost of $6,000 with total annual maintenance costs of $750. Machine B has an initial cost of $8,500 with total annual maintenance costs of $405. At a 8% interest rate, in approximately how many years do the two machines have the same present worth? Two machines are to be compared with each other, based on their present worth. Machine A has an initial cost of $6,000 with total annual maintenance costs of $750. Machine B has an initial cost of $8,500 with total annual maintenance costs of $405. At a 8% interest rate, in approximately how many years do the two machines have the same present worth?.