If it takes five hours for one person to paint one classroom, how many hours would it take to paint 36 classrooms?

180 hours

With a team of 4, it would take five hours to finish painting 4 classrooms. If they wanted to paint all 36 classrooms, how many sets of classrooms would they have to paint, or how may would each person have to paint?

36 ÷ 4 = 9 sets

Based on part (a), all 36 classrooms would take a total of 180 hours of work.

20 people