To obtain a 15% solution in a 2.8 gallon tank, how many gallons of active product must be added?

To obtain a 15% solution in a 2.8 gallon tank, how many gallons of active product must be added?

• A. 0.20
• B. 0.42
• C. 0.60
• D. 0.10

Answer: (B)

To hit a 15% concentration in a 2.8-gallon tank, the amount of active product you need is 15% of the total volume. Multiply 2.8 gallons by 0.15, which equals 0.42 gallons. So, add 0.42 gallons of active product and the remaining 2.38 gallons will be the other components to reach the full 2.8 gallons. This checks out because 0.42 divided by 2.8 equals 0.15, or 15%. The other amounts would yield different concentrations (for example, 0.20 gallons gives about 7.1%, 0.60 gallons about 21.4%, and 0.10 gallons about 3.6%).