Texas Class A Barber Written ExamSanitation, Disinfection, and SafetyMedium
A barber is preparing a disinfectant solution. The label states a 1:100 dilution ratio. If the barber needs to make 2 gallons of solution, how much disinfectant concentrate should be used?
- A1.28 fluid ounces
- B0.64 fluid ounces
- C2.56 fluid ounces
- D2.00 fluid ounces
Show answer & explanationAnswer & explanation
Correct answer: C. 2.56 fluid ounces
To calculate the amount of concentrate, first convert 2 gallons to fluid ounces (2 gallons * 128 fl oz/gallon = 256 fl oz). Then, divide the total volume by the dilution ratio (256 fl oz / 100 = 2.56 fl oz).
Why the other options are wrong
- A. This is half of 2.56 fl oz, which would be a 1:200 dilution for 2 gallons.
- B. This is a quarter of 2.56 fl oz, indicating an incorrect calculation or ratio.
- D. This would be 1 gallon diluted at 1:64 or 2 gallons diluted at 1:128, not 1:100.
Dilution Ratio Calculation
The process of determining the correct amount of concentrate needed to achieve a specified dilution ratio for a given total volume of solution.
- Ratio is concentrate:water or concentrate:total solution
- Requires consistent units (e.g., fluid ounces)
- 1 gallon = 128 fluid ounces
Memory trick: Gallons to Ounces, Then Divide by Ratio