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Also include explanation of mathematical formula used to obtain the answer so that I may learn and practice.

Make sure if using a financial calculator tell me the formula used and numbers to input.

You are starting a family pizza parlor and need to buy a motorcycle for delivery orders. You have two models in mind. Model A costs $$9,000$ and is expected to run for six years; model B is more expensive, with a price of $$14,000$ and has an expected life of $10$ years. The annual maintenance costs are $$800$ for model A and $$700$ for model B$.$ Assume that the opportunity cost of capital is $10$ percent.

Which one should I buy and why?

Hint: Calculate the net present value $($NPV$)$ of each motorcycle and then compute the equivalent annual cost $($EAC$).$ Note that since we are dealing with all negative cash flows $($costs$),$ we are looking for the alternative with the least negative EAC.

Initial Investment $($A$)$: $$9,000$

Initial Investment $($B$)$: $$14,000$

Life in Years $($A$)$: $6$

Life in Years $($B$)$: $10$

Annual Maintenance Costs $($A$)$: $$800$

Annual Maintenance Costs $($B$)$: $$700$

Cost of Capital: $10\mathrm{.}00\%$