We are told that the boat can travel 25 miles upstream in 5 hours. That comes to
25 miles
------------ = 5 mph.
5 hours
In the same 5 hours, that boat can travel 50 miles downstream. That comes to
50 miles
------------ = 10 mph
5 hours
Was there more to this question than the above?
Note: "It can go 50 miles downstream IN the same time (5 hours)."
