SOLUTION: You have 3 gallons of punch that is 7% alcohol. A friend pours in 3 gallons of their punch and now the combined mix is 9% alcohol. What % alcohol was the added 3 gallons of punch?

Algebra ->  Equations -> SOLUTION: You have 3 gallons of punch that is 7% alcohol. A friend pours in 3 gallons of their punch and now the combined mix is 9% alcohol. What % alcohol was the added 3 gallons of punch?      Log On


   

Question 169367: You have 3 gallons of punch that is 7% alcohol. A friend pours in 3 gallons of their punch and now the combined mix is 9% alcohol. What % alcohol was the added 3 gallons of punch?
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
let x be the % of alcohol in the added 3 gallons
:
.07(3)+x(3)=.09(6)
:
.21+3x=.54
:
3x=.33
:
highlight%28x=11%29 percentage of alcohol in added 3 gallons