Joe Schmoe has already driven 58 miles of a long road trip. He drives at an average of 45 miles per hour the rest of the way. The total trip is 508 miles, how many hours did this trip take Joe Schmoe?
508 - 58 = 450 miles. He's driving 45 miles per hour over 450 miles, which means it took him 450/45 = 10 hours to drive the rest of the way