SOLUTION: How much pure acid should be mixed with 7 gallons of a 40% acid solution in order to get an 80% acid solution?

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: How much pure acid should be mixed with 7 gallons of a 40% acid solution in order to get an 80% acid solution?      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 159555: How much pure acid should be mixed with 7 gallons of a 40% acid solution in order to get an 80% acid solution?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
How much pure acid should be mixed with 7 gallons of a 40% acid solution in order to get an 80% acid solution?
------------
acid + acid = acid
0.40*7 + 1.00x = 0.80(7+x)
40*7 + 100x = 80(7+x)
280 + 100x = 560 80x
20x = 280
x = 14 gallons (amount of 100% acid that must be added)
============
Cheers,
Stan H.