Approximately how many gallons does the tank hold when full?

• A. 1,000,000
• B. 2,100,000
• C. 3,000,000
• D. 4,000,000

Answer: (B)

What this question tests is turning a tank’s physical size into gallons by calculating its volume. For a cylindrical tank, you’d take the diameter, get the radius (half the diameter), and compute V = π r^2 h. After you have the volume in cubic feet, convert to gallons with 1 ft^3 ≈ 7.48 gallons. If the dimensions given in the problem yield a volume around 280,000 ft^3, that translates to about 2,100,000 gallons when you multiply by 7.48, which is why the approximate full-tank capacity lands near two million one hundred thousand gallons. If the tank were another shape, you’d use the appropriate volume formula, but the same conversion step applies: determine volume in cubic feet, then convert to gallons and round.