A boat traveled 252 miles downstream and back the trip downstream took 12 hours the trip back took 84 hours what is the speed of the boat in still water what is the speed of the current

The boat traveled 252 miles downstream, so it means that the distance traveled by the boat is 252 miles. The speed of the boat is exactly 21 miles per hour and in going back is 3 miles per hour. In my prediction, the speed of the current should not be greater than 3 miles per hour. So the best answer would be 2 miles per hour.