# 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?

Apr 28, 2016

The amount of higher concentration used is 60%
The amount of lower concentration used is 40%

#### Explanation:

There is a trick to this that I discovered when my job was blending of different concentrations.

Let the % amount of higher concentration be $x$

Then by ratio

$\frac{12 - 2}{100} = \frac{8 - 2}{x}$

$\implies \frac{x}{6} = \frac{100}{10}$

=>x=6xx10=60%
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Check:

$\left(\frac{60}{100} \times 12\right) + \left(\frac{40}{100} \times 2\right) = 8 \text{ }$as required