An area of 200 square feet yields an average of 26 ounces of water in 30 seconds with a backpack sprayer. What is the output in gallons per minute?

• A. 0.2
• B. 0.4
• C. 0.6
• D. 0.8

Answer: (B)

This question is about converting the spray output to a standard flow rate in gallons per minute. Start with how much is delivered in a fixed time, then convert to gallons.

26 ounces in 30 seconds scales up to 52 ounces in 60 seconds (1 minute). Since 1 gallon equals 128 ounces, 52 ounces is 52/128 gallons, which equals about 0.406 gallons per minute. Rounding gives roughly 0.4 gallons per minute.

The area (200 square feet) isn’t needed to determine the output rate in GPM; it would be used later if you wanted to compute spray coverage per area (for example, gallons per 1,000 square feet) by multiplying the GPM by 1000 divided by the area.