# How much pure acid should be mixed with 5 gallons of a 20% acid solution in order to get a 50% acid solution?

##### 1 Answer

Nov 17, 2016

3 gallons

#### Explanation:

So we know that we're adding pure acid, so that would be 100%. We don't know how much pure acid we're adding, so we'll designate

Simplifying, we get

So we need 3 gallons of pure acid.