posted by kay .
Water is filled into a tank of base 40 cm x 40 cm. the water level rises 7.5 cm when 5 identical small marbles and 5 identical large marbles are into into the tanks and sick. If the volume of a large marble if two times that of the small one, what are the volumes of the marbles?
5Vsm + 5Vlm= 40x40x7.5 cm^2
substutited 10 Vsm for the 5Vlm, and solve.