<PRE><B>Question 986344</B>
mary wants to make 20 gal. of a 52% acid solution by mixing together a 84% acid solution and a 4% acid solution. how much of each must she use?

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e = amount of 84%
f = amount of 4%
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e + f = 20 (total solution)
84e + 4f = 20*52  (total acid)
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