Joey drives a golf cart when he needs to monitor the security of his neighborhood. He can cover the 40 miles of streets in his neighborhood in 2...

Joey drives a golf cart when he needs to monitor the security of his neighborhood. He can cover the 40 miles of streets in his neighborhood in 2 hours. What unit rate expresses the speed of Joey's golf cart per hour?

 10 miles per hour

 15 miles per hour

 20 miles per hour

 30 miles per hour