Problema Solution
A pharmacist mixed some 10% - saline solution with some 15% -saline solution to obtain 100mL of a 12% salie solution. How much of the 1-% saline solution did the pharmacist use in the mixture.
Answer provided by our tutors
The total amount of solution is 100 mL and it contains 12% saline, or 12 parts saline.
The mixture is made up of 10% saline and 15% saline, so we get the following equation:
.12(100 mL) = .10(x) + .15(100mL - x)
And solving we get:
12 mL = .1x mL + 15 mL - .15x mL
.05x = 3 mL
x = 60 mL
The solution was made up of 60 mL 10% solution and 40 mL 15% solution yielding 100 mL 12% solution.
ANSWER: 60 mL of 10% saline solution were used.