To get to his parents house John must travel at a speed of 60 mph on land and then use a motorboat that travels at a speed of 20 mph in still water John goes by land to a dock and then travels on a?

To get to his parents house John must travel at a speed of 60 mph on land and then use a motorboat that travels at a speed of 20 mph in still water John goes by land to a dock and then travels 138 miles.