The question in this problem is only for the replace in $1$ year decision. This is a partial question exam created to give credit for partial work $($individual steps in a problem$).$

You are facing the decision of whether to replace an old machine at your factory. A new machine will cost $$20$ to purchase it now and the yearly maintenance expenses will be $$8$ a year. The new machine has a life of $5$ years at which time it is estimated it can be sold for $$12.$ The new machine will be depreciated down to zero over $5$ years using straight$-$line depreciation. If the new machine is purchased, the old machine can be sold today for $$16.$ However, if the old machine is not replaced today, it will continue to be depreciated down to zero using straight$-$line method over its remaining $4$ years. The book value of the old machine today is $$6.$ It is estimated that the old machine can be sold for $$4$ in one year $($at the end year $1).$ The maintenance cost per year for the old machine will be $$7.$ Assume that the discount rate is $10\%$ and the tax rate is $20\%.$

In answering the question, round to nearest dollar, DO NOT USE commas to separate thousands, and do not use the dollar $($$$)$ sign; do not enter decimals. For example if your answer is $-$$$12\mathrm{.}534$ then enter $-13$; if answer is $$23\mathrm{.}7459$ then enter $24$; if the answer is $-$$$40$ then enter $-40$

The opportunity cost today $($t$=0)$ for the replace $1-$year later decision is