Volume = Length × Width × Height
Volume = 72 in × 22 in × 18 in
Volume = 29,952 cubic inches
To convert cubic inches to gallons, we need to divide the volume in cubic inches by 231, which is the number of cubic inches in a gallon.
Volume (gallons) = Volume (cubic inches) / 231
Volume (gallons) = 29,952 cubic inches / 231
Volume (gallons) ≈ 130 gallons
Therefore, a 72 inch x 22 inch x 18 inch cube can hold approximately 130 gallons of water.