555 people are painting the walls for 20 minutes.
that means that each one of them works for only 20 minutes, however there are 555 of them. So the "total minutes worth" of work is 555 * 20 minutes, or 11100 minutes.
that's for 5 walls, how about for just one wall? well 11100/5 or 2220 minutes it takes in "total minutes worth" to do just one wall.
how many minutes will it take 9 people to do just one at that same rate?
[tex]\bf \cfrac{2220}{9}\qquad \textit{how about to do 9 walls?}\qquad \cfrac{2220}{9}\cdot 9\implies 2220[/tex]
how many hours is that anyway? since there are 60 minutes per hour, then is 2220/60 or just 37 hours.
