An outboard motor boat can pull a water skier at a cruising speed of 28mi/h in still water?

An outboard motor boat can pull a water skier at a cruising speed of 28mi/h in still water. the boat takes a skier for a ride in a river that flows at 6mi/h . the boat takes the skier upstream and then returns home. the trip takes one hour. how far upstream does it travel? Read more »