Sixth Grade Challenging Math

681) Answer
22.86 inches
Solution: The volume of the water
in the tank is 10 * 40 * 40 cubic inches. The area of the base of the
cubic shaped metal is 30 * 30 = 900 square inches. After the metal piece is placed in
the fish tank, the area of the base is reduced to 40^{2}  30^{2}
square inches. The volume of water remains unchanged. Therefore, the height of the water level is:
(10 * 40 * 40)/(40^{2}  30^{2}) = 22.86 inches
* means multiply
