Question

How much of a 60% acid solution must be mixed with 50 gallons of a 24% acid solution to obtain a solution that is 50% acid?

Answer 1

For these problems they often have you make this little chart. For some people it make sense, for others no, but lets see.
We have 60% of something, 24% of something and these must combine to equal 50% of something. Now the 60% quantity we dont know, we know the 24% quantity, and we dont know the 50% acid quantity. So here's the chart set-up based off what we know:



So as you read left to right, you add, as you go top to bottom, you multiply. The bottom row is the final result and the problem we must solve. That is just a common way to set it up. So we have:

.60x + 12 = .50(x+50) Now its just solving.