Two pieces of equipment are being considered by a chemical plant.

Brand A will cost $$30,000$ and will have an annual operating and maintenance $($O&M$)$ cost of $$5000$ over

its six year life with a salvage value of $$3000$

Brand B will cost $$15,000$ and will have O&M cost of $$8000$ over the first three years and $$10,000$ over

the last three years of its six year life with negligible salvage value.

Which brand of equipment should the chemical plant choose? Take i$=10\%$