Your half-acre plan uses a pesticide labeled 1 quart per acre. A sprayer with a 4-gallon tank is calibrated to 20 gpa. How much pesticide should you add to each full tank?

Your half-acre plan uses a pesticide labeled 1 quart per acre. A sprayer with a 4-gallon tank is calibrated to 20 gpa. How much pesticide should you add to each full tank?

• A. 0.1 quart
• B. 0.2 quart
• C. 0.5 quart
• D. 1 quart

Answer: (B)

The key idea is to match the pesticide amount to the area you’ll cover with one full tank at the given spray volume. A label rate of 1 quart per acre means you need 1 quart to treat 1 acre. With a 4-gallon tank and a spray rate of 20 gallons per acre, one full tank covers 4 ÷ 20 = 0.2 acres. Multiply by the label rate: 0.2 acres × 1 quart/acre = 0.2 quart to mix in the tank. (For another way: 1 quart per acre is 0.25 gallon per acre. Treating 0.2 acres uses 0.2 × 0.25 = 0.05 gallons, which converts to 0.05 × 4 = 0.2 quart.) So, you should add 0.2 quart to each full tank.

The key idea is to match the pesticide amount to the area you’ll cover with one full tank at the given spray volume.

A label rate of 1 quart per acre means you need 1 quart to treat 1 acre. With a 4-gallon tank and a spray rate of 20 gallons per acre, one full tank covers 4 ÷ 20 = 0.2 acres. Multiply by the label rate: 0.2 acres × 1 quart/acre = 0.2 quart to mix in the tank.

(For another way: 1 quart per acre is 0.25 gallon per acre. Treating 0.2 acres uses 0.2 × 0.25 = 0.05 gallons, which converts to 0.05 × 4 = 0.2 quart.)

So, you should add 0.2 quart to each full tank.