When 2 paint brands breakeven? (enginnering economy)?

brand A (15.8$/gallon,every gallon is sufficient to 350 square ft ,lasts 3 yrs,70 square ft could be painted every hour)


brand B(20.4$/gallon, sufficient to 400 square ft,80 square ft could be painted everyhour)


the worker takes 17 $ per hour


rate of iterest is 10%


how lond does brand b have to last so they BREAKEVEN?When 2 paint brands breakeven? (enginnering economy)?
Brand A will cost:


Cost of paint $15,80


Labor cost 350/70 * 17-$85.00


Total--$100.80


Interest for 3 years @10%-$30.24


Total-$140.04


Cost per year $140.04/3 years--$43.68





Brand B will cost before interest $20.40+85=105.40


In order to break even the time required will be


($140.04/105.40) - 1= 3.29 years