Rhode Island Journeyman Plumber Practice Exam

How many gallons of water are in a tank that is 24" round and 60" high?

1. 100 gallons

2. 117.5 gallons

3. 150 gallons

4. 60 gallons

The correct answer is: 117.5 gallons

To determine how many gallons of water are in a cylindrical tank, you can use the volume formula for a cylinder, which is: Volume = π × r² × h In this equation, r is the radius of the cylinder, and h is the height. Since the tank in question is 24 inches round, the diameter is 24 inches, giving a radius of 12 inches (half of the diameter). The height of the tank is given as 60 inches. First, calculate the volume in cubic inches: 1. Convert the radius to inches: r = 12 inches 2. Plug the values into the formula: Volume = π × (12 inches)² × 60 inches Volume = π × 144 inches² × 60 inches Volume = π × 8640 inches³ 3. Approximate π as 3.14 for a quick calculation: Volume ≈ 3.14 × 8640 ≈ 27154.4 cubic inches. Next, convert cubic inches to gallons. There are 231 cubic inches in one gallon. 4. To convert, divide the volume in cubic inches by 231: Volume in gallons ≈ 27154