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| Question 25921:  Ooops.  I just asked one question and was looking at the other problem.  Sorry.
 Here is the correct question and the way I set it up.
 60 fluid ounces of a 15% muriatic acid solution is needed to kill algae in a pool.  If the technician has a 5% solution and a pure solution on hand, how many ounces of each must be combined to create the 15% solution?
 I don't even know how I would set this one up, I know I am supposed to be seeing a pattern on how to set mixture problems up, but I keep putting the wrong numbers in the wrong places.
 Thanks for your help.
 Donna
 Answer by longjonsilver(2297)
      (Show Source): 
You can put this solution on YOUR website! OK, first define what you need. 
 Let x = volume of 5% acid.
 
 Now for the leap of faith part...how much of the pure acid is needed? Answer is (60-x)! This is the hardest part done now.
 
 Now for the solution.
 BEFORE = AFTER
 
 0.05x + 1.00(60-x) = 0.15*60
 0.05x + 60 - x = 9
 -0.95x = -51
 --> x = -51/-0.95
 x = 53.68 fl.oz (to 2 dp)
 
 so we need 53.68 fl.oz of the 5% acid and we will need 6.32 fl.oz of the pure acid too.
 
 jon.
 
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