How much water in a 24x12x16 fish tank?

The volume of a rectangular prism (such as a fish tank) is calculated by multiplying the length, width, and height. In this case, the length is 24 inches, the width is 12 inches, and the height is 16 inches. So, the volume is:

$$V = lwh = (24 \text{ in})(12 \text{ in})(16 \text{ in}) = 4608 \text{ in}^3$$

To convert cubic inches to gallons, we divide by 231 (the number of cubic inches in a gallon):

$$V = \frac{4608 \text{ in}^3}{231 \text{ in}^3/\text{gal}} \approx 19.95 \text{ gal}$$

Therefore, a 24x12x16 fish tank can hold approximately 19.95 gallons of water.