You are spraying a corn field for stalk borers along the field edge with 3 pints per acre, treating only the outside eight rows on 30-inch rows, for a strip one mile long. How many pints of insecticide are required?

You are spraying a corn field for stalk borers along the field edge with 3 pints per acre, treating only the outside eight rows on 30-inch rows, for a strip one mile long. How many pints of insecticide are required?

• A. 3.75 pints
• B. 5 pints
• C. 7.25 pints
• D. 12.5 pints

Answer: (C)

You're calculating how much insecticide is needed based on the area treated, since the rate is expressed per acre. First find the strip width: eight rows at 30 inches apart gives 8 × 30 = 240 inches, which is 20 feet. The strip length is one mile, which is 5280 feet. So the area treated is 20 ft × 5280 ft = 105,600 square feet. Convert to acres: 1 acre = 43,560 square feet, so treated acres = 105,600 / 43,560 ≈ 2.424 acres. Apply the rate: 3 pints per acre × 2.424 acres ≈ 7.272 pints. The option that best matches this calculation is about 7.25 pints.

You're calculating how much insecticide is needed based on the area treated, since the rate is expressed per acre.

First find the strip width: eight rows at 30 inches apart gives 8 × 30 = 240 inches, which is 20 feet. The strip length is one mile, which is 5280 feet. So the area treated is 20 ft × 5280 ft = 105,600 square feet.

Convert to acres: 1 acre = 43,560 square feet, so treated acres = 105,600 / 43,560 ≈ 2.424 acres.

Apply the rate: 3 pints per acre × 2.424 acres ≈ 7.272 pints. The option that best matches this calculation is about 7.25 pints.