Texas Class A Barber Written ExamSanitation, Disinfection, and SafetyMedium
A barber is using a disinfectant that requires a 1:10 dilution ratio. If the disinfectant container holds 20 ounces of concentrate, how much water is needed to prepare the entire container of concentrate for use?
- A180 ounces
- B200 ounces
- C10 ounces
- D20 ounces
Show answer & explanationAnswer & explanation
Correct answer: B. 200 ounces
A 1:10 dilution means 1 part concentrate to 10 parts water. If you have 20 ounces of concentrate, you need 10 times that amount in water (20 oz * 10 = 200 oz).
Why the other options are wrong
- A. 180 ounces of water would result in a 1:9 dilution, which is incorrect.
- C. 10 ounces of water would result in a 2:1 dilution, which is incorrect.
- D. 20 ounces of water would result in a 1:1 dilution, which is incorrect.
Dilution Ratio Calculation
To calculate the amount of water needed for a dilution ratio, multiply the amount of concentrate by the 'parts water' number in the ratio.
- Ratio X:Y means X parts concentrate to Y parts water.
- Multiply concentrate amount by Y to find water needed.
- Crucial for disinfectant efficacy and safety.
Memory trick: Dilution: Concentrate times Ratio's Water Part.