Allison needs 18 liters of a 5% saline solution.

Question

She has a 1% solution and a 10% solution available.

How many liters of the 1% solution and how many liters of the 10% solution should she mix to make the 5% solution?

Answer 1

x liters of 1% solutions.

Then, we get equation: 0.01x + 0.1(18 - x) = 0.05·18;

x + 180 - 10x = 90; 9x = 90; x = 10 l;

Answer: 10 l of 1% sol and 8 l of 10% sol