SOLUTION: How many gallons of a 3% salt solution must be mixed with 30 gallons of a 9% solution to obtain a 6% solution?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: How many gallons of a 3% salt solution must be mixed with 30 gallons of a 9% solution to obtain a 6% solution?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 414232: How many gallons of a 3% salt solution must be mixed with 30 gallons of a 9% solution to obtain a 6% solution?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
percent ---------------- quantity
9 ---------------- 30
3 ---------------- x
6 ---------------- 30+x
...
9*30+3*x =6(30+x)
270+3x=180+6x
3x-6x=180-270
-3x=-90
/-3
x=30 liters