FAA Aviation Mechanic General (AMG)Physics, Math and Fluid LinesHard
A rectangular hydraulic fluid tank measures 24 inches long, 18 inches wide, and 12 inches deep. Approximately how many gallons does the tank hold when full (1 cubic foot = 7.48 gallons)?
- A22.4 gallons
- B7.5 gallons
- C3.0 gallons
- D44.9 gallons
Show answer & explanationAnswer & explanation
Correct answer: A. 22.4 gallons
Convert dimensions to feet: 2 ft × 1.5 ft × 1 ft = 3 cubic feet. Then convert to gallons: 3 ft³ × 7.48 gal/ft³ = 22.44 gallons.
Why the other options are wrong
- B. Simply restates the conversion factor without applying tank volume.
- C. Correct cubic footage but forgets to convert to gallons.
- D. Results from doubling the correct volume in gallons.
Volume-to-Gallon Conversion
To convert a tank's cubic volume to gallons, calculate volume in cubic feet and multiply by 7.48 gallons per cubic foot.
- 1 cubic foot = 7.48 U.S. gallons
- Convert all dimensions to feet before calculating volume
- Volume of rectangular tank = length × width × height
- Common in fuel and hydraulic reservoir sizing problems
Memory trick: Feet cubed times 7.48 turns a box into gallons.