Question

A pharmacist must mix 12 fl oz of cough syrup that contains 25% active ingredient with flavored syrup that contains no active ingredient. How many fluid oz of flavored syrup must the pharmacist add to create a mixture containing 10% active ingredient?

Answer 1

So this needs 10% active ingredient.

0.1*12 fl oz = 1.2 fl oz active ingredient

1.2 fl oz act. ing * (100 oz/ 25 oz act. ingredient) = 4.8 fl. oz

12 fl. oz - 4.8 fl. oz = 7.2 fl oz syrup

Answer 2

This is only correct if the concentration is by volume. percentages wouldn't happen to be in g/100 mL, would they?

Answer 3

Oh and it's not the pharmacists who mix these, it's the techs. The techs do EVERYTHING.