Question

How many gallons of a 15% acid solution must be mixed with 5 gallons of a 20% acid solution to make a 16% acid solution?

Answer 1

`20` gallons

Explanation:

`0.15x + 0.2 xx 5 = 0.16(x+5)`
`0.01x = 0.2`
`x = 20` gallons