Hayden Inc. has a number of copiers that were bought four years ago for $$33,000.$ Currently maintenance costs $$3,300$ a year, but the

maintenance agreement expires at the end of two years, and thereafter, the annual maintenance charge will rise to $$9,300.$ The

machines have a current resale value of $$9,300,$ but at the end of year $2,$ their value will have fallen to $$4,800.$ By the end of year $6,$

the machines will be valueless and would be scrapped.

Hayden is considering replacing the copiers with new machines that would do essentially the same job. These machines cost

$$28,000,$ and the company can take out an eight$-$year maintenance contract for $$1,600$ a year. The machines would have no value by

the end of the eight years and would be scrapped.

Both machines are depreciated using seven$-$year straight$-$line depreciation, and the tax rate is $35\%.$ Assume for simplicity that the

inflation rate is zero. The real cost of capital is $7\%.$

a$.$ Calculate the equivalent annual cost, if the copiers are: $($i$)$ replaced now, $($ii$)$ replaced two years from now, or $($iii$)$ replaced six years

from now. $($Do not round intermediate calculations. Enter your answers as a positive value rounded to $2$ decimal places.$)$

b$.$ When should Hayden replace its copiers?