It takes a ship 3 hours to cover 72 km with the current and 4 hours against the current. Find the speed of the ship in still water and the speed of the current.
Hey kid! The ship's speed relative to the water plus the speed of the water is 24 km/h. The ship's speed relive to the water minus the speed of the water is 18 km/h.
The difference logically is twice the speed of the water, so that is 3 km/h. This leaves a speed of 21 km/h for the boat in still water. Another way to show this would be this Vs+Vc = 72/3 = 24 m/sec Vs-Vc = 72/4 = 18 m/sec subtracting one from the other : 2Vc = 24-18 = 6.0 m/sec Vc = 3.0 m/sec. Hope this helps ~Nadia~
