If a fish tank is 20 inches long 20 inches tall and 12 inches wide how many gallons of water will it hold?

To calculate the volume of the fish tank, first find the volume in cubic inches: 20 inches (length) × 20 inches (height) × 12 inches (width) = 4,800 cubic inches. Since there are 231 cubic inches in a gallon, divide 4,800 by 231, which equals approximately 20.8 gallons. Therefore, the fish tank will hold about 20.8 gallons of water.