SOLUTION: Otto's car radiator contains 20 quarts of a 25% antifreeze solution. How many quarts of this solution must be drawn off and replaced with pure antifreeze so the radiator is filled

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: Otto's car radiator contains 20 quarts of a 25% antifreeze solution. How many quarts of this solution must be drawn off and replaced with pure antifreeze so the radiator is filled       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 721399: Otto's car radiator contains 20 quarts of a 25% antifreeze solution. How many quarts of this solution must be drawn off and replaced with pure antifreeze so the radiator is filled with a 40% solution?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Draw off and replace v quarts.
%2820%2A25-v%2A25%2Bv%2A100%29%2F20=40.

Be sure to understand how that equation is made and works. Volumes before and after are the same. Some pure antifreeze will be removed and this is v*25% but this missing volume will be replaced with pure antifreeze material.
Next, simplify and solve for v.