SOLUTION: Please help me with this. Marion wants to dilute 2 gal of a 28% soap solution to make a 8% solution. How much pure water should she add to make the 8% solution?

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Question 30788: Please help me with this. Marion wants to dilute 2 gal of a 28% soap solution to make a 8% solution. How much pure water should she add to make the 8% solution?
Found 2 solutions by Fermat, checkley71:
Answer by Fermat(136) (Show Source):
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2 gall of 28% soap solution
This comprises of 28% of 2 gall = 0.56 gall of pure soap + 1.44 gal of pure water.
Let Marion add n gall of pure water.
Total volume = n+2 gall
Concentratiuon of soap = 0.56 gall/(n+2) gall and this is to equal 8% = 0.08
0.56/(n+2) = 0.08
0.56 = 0.08(n+2)
0.56 = 0.08n + 0.16
0.40 = 0.08n
8n = 40
n = 5
Ammount of water to be added is,
n = 5 gallons
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Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website!
(2x.28)=(X+2).08 or .56=.08X+.16 or .40=.08X or x=.40/.08 or X=5 gal.