William has a 262626-liter glass tank. First, he wants to put some marbles in it, all of the same volume. Then, he wants to fill the tank with water until it's completely full. If he uses 858585 marbles, he will have to add 20.920.920, point, 9 liters of water. What is the volume of each marble? liters How much water is necessary if William uses 200200200 marbles? liters