Police officer A patrols 36 streets in 4 hours. His colleague, officer B, patrols 55 streets in 5 hours. How many streets will both officers patrol in one hour?
Officer A patrols 36 streets / 4 hours = <<36/4=9>>9 streets/hour.
Officer B patrols 55 streets / 5 hours = <<55/5=11>>11 streets/hour
Together officer A and B patrol 9 streets/hour + 11 streets/hour = <<9+11=20>>20 streets/hour.
#### 20