To deliver a package, a messenger should travel at speed of 60 miles per hour on land and then employ a motorboat whose speed is 20 miles per hour in still water. The messenger goes by land to a dock and then travels on a river against a current of 4 miles per hour. He reaches his destination in 4.5 hours and then returns to the starting point in 3.5 hours. How far did the messenger travel by land and how far by water?