William has a 26-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 85 marbles, he will have to add 20.9 liters of of water. what is the volume of each marble? How much water is necessary if william uses 200 marbles?
The volume of the marbles is 26-20.9 = 5.1 l and there ar e85 marbles
5.1/85 = .06 l/marble
then 200 marbles would requrie .06 l/marble x 200 marbles = 12 liters
so he would only need 26-12= 14 liters of water to fill the tank !