A custodian has to clean a school with 80 classrooms. They have 5 days to get it done. It takes them 15 minutes per classroom. If they work an 8 hour day, what percentage of their day, on average, is spent cleaning classrooms?
They have to clean 16 classrooms a day because 80 / 5 = <<80/5=16>>16
They spend 240 minutes cleaning per day because 16 x 15 = <<16*15=240>>240
They spend 4 hours a day because 240 / 60 = <<240/60=4>>4
They spend half their day cleaning classrooms because 4 / 8 = <<4/8=.5>>.5
They spend 50% of their day cleaning classrooms because .5 x 100 = <<.5*100=50>>50
#### 50