A 2% solution of sulfuric acid was mixed with a 12% solution of sulfuric acid to produce an 8% solution. How do you determine how much 2% solution and how much 12% solution were used to produce 10 gallons of 8% solution?
The amount of higher concentration used is
The amount of lower concentration used is
There is a trick to this that I discovered when my job was blending of different concentrations.
Let the % amount of higher concentration be
Then by ratio