SOLUTION: HOW much water must be mixed with 9 pints of 70% developer to produce a mixture that is 25% developer?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: HOW much water must be mixed with 9 pints of 70% developer to produce a mixture that is 25% developer?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 166035: HOW much water must be mixed with 9 pints of 70% developer to produce a mixture that is 25% developer?
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
.70*9=.25(9+x)
6.3=2.25+.25x
.25x=6.3-2.25
.25x=4.05
x=4.05/.25
x=16.2 pints of water is needed.
Proof:
.70*9=.25(9+16.2)
6.3=.25*25.2
6.3=6.3