How many gallons of distilled water must be mixed with 50 gallons of a 30% alchohol solution to get a 25% solution?

1 answer

A 30% solution (I assume we are talking about volume/volume percent here) is 30 gallons alcohol + 70 gallons water OR
[30 gallons alcohol/(30 gal alcohol+70gal water)]*100. 50 gallons of a 30% solution would contain 15 gal alcohol + 50 gal solution (or 15 gal alcohol + 35 gal water).
[(15 gal alcohol)/(15 gal alc+35 gal water+ x gal water)]*100.
Solve for x gal water. Check my thinking. Check my work.