A motorboat went 70 miles in 4 hours when traveling at full speed upstream on a river whose current flows at the rate of 6 miles per hour. how fast can the boat travel in still water?
Let 'x' be the speed of boat in still water ----------------- x - 6mph = 70mi/4hr x - 6mph = 17.5 mph x = 17.5 + 6 x = 23.5 mph ---------------- Therefore the boat has a speed of 23.5mph in still water.
