Two identical tanks are 3 ft in diameter and 3 ft high, and they are both vented to the atmosphere. The top of tank B is level with the bottom of tank A, and they are connected by a line from the bottom of A to the top of B with a valve in it. Initially A is full of water, and B is empty. The valve is opened for a short time, letting some of the water drain into B. An inverted manometer having an oil with SG 0.7 is connected between taps on the bottom of each tank. The manometer reading is 6 in., and the oil/water interface in the leg connected to tank A is higher. What is the water level in each of the tanks?