If a herbicide label indicates a mix rate of 20 gallons of product in 100 gallons of mix, how much product is needed for 25 gallons of spray?

• A. 3 gallons
• B. 5 gallons
• C. 7 gallons
• D. 10 gallons

Answer: (B)

To determine how much product is needed for 25 gallons of spray, you start with the mixing ratio given on the herbicide label: 20 gallons of product should be mixed with 100 gallons of total mixture. This means that the product constitutes 20% of the total mixture (since 20 gallons is 20% of 100 gallons).

To find out how much product is required for 25 gallons of spray, you calculate 20% of 25 gallons.

First, you can express the product's ratio in a formula:

[ \text{Amount of product} = \frac{\text{Product in gallons}}{\text{Total mixture in gallons}} \times \text{Desired volume of spray} ]

Using the values:

[ \text{Amount of product} = \frac{20}{100} \times 25 = 5 \text{ gallons} ]

Thus, for 25 gallons of spray, you need 5 gallons of the herbicide product. This clearly shows how the proportion based on the label converts into the required amount for a smaller mixture. The calculation aligns with option B as the correct quantity needed for the specified volume of the spray.