You need to calculate the volume of water in a 50-foot long, 2-inch diameter pipe. The radius is 1 inch. Using the formula Volume = π × r² × L, and knowing there are 7.48 gallons per cubic foot, approximately how many gallons of water does the pipe contain? (Note: 1 foot = 12 inches)

• About 10.5 gallons
• About 6.5 gallons
• About 4.1 gallons
• About 8.2 gallons