A fish tank at an aquarium contains several cubic feet of water (1 cubic foot of water = 62.5 pounds). If the fish tank is 6 feet deep, 12 feet wide, and 13 feet long, what’s the approximate pressure at the bottom of the tank in pounds per square inch?

To find the pressure (psi), we must divide the tank’s total volume by the surface area of the bottom of the tank. The volume = 6 × 12 × 13 = 936 feet. Multiply it by 62.5 to convert it into pounds: 936 × 62.5 = 58,500. The bottom of the tank’s surface area is
12 ft × 13 ft = 156 inches.
Since pressure is in pounds per square inch (psi), we have to convert it to inches. The surface area is 22,464 inches. The psi is 58,500 ÷ 22,464 which is approximately 2.6. The closest answer is 2.5.