NIC Barber Written (Theory) ExamScientific ConceptsEasy

A barber is preparing a new batch of disinfectant solution. The manufacturer's instructions state to mix 2 ounces of concentrated disinfectant with 1 gallon of water. If the barber needs to make 3 gallons of solution, how much concentrated disinfectant is required?

  1. A6 ounces
  2. B12 ounces
  3. C8 ounces
  4. D4 ounces
Show answer & explanation

Correct answer: A. 6 ounces

The ratio is 2 ounces of concentrate per 1 gallon of water. If you need 3 gallons of water, you multiply the concentrate amount by 3 (2 ounces/gallon * 3 gallons = 6 ounces).

Why the other options are wrong

  • B. 12 ounces would be for 6 gallons, not 3.
  • C. 8 ounces would be for 4 gallons, not 3.
  • D. 4 ounces would be for 2 gallons, not 3.

Disinfectant Dilution

The process of mixing concentrated disinfectant with water to achieve the correct working strength.

  • Follow manufacturer's instructions precisely.
  • Incorrect dilution can render disinfectant ineffective or damaging.
  • Measured ratios ensure proper germicidal action.

Memory trick: Multiply the part by the whole.

More Scientific Concepts questions