SOLUTION: two gasahol mixtures are available one contains4.5%alcohol,and the other contains9.75%alcohol.How much of each do you need to mix up 300 liters of gasahol containing 7.25%alcohol

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: two gasahol mixtures are available one contains4.5%alcohol,and the other contains9.75%alcohol.How much of each do you need to mix up 300 liters of gasahol containing 7.25%alcohol      Log On

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Question 125825: two gasahol mixtures are available one contains4.5%alcohol,and the other contains9.75%alcohol.How much of each do you need to mix up 300 liters of gasahol containing 7.25%alcohol
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let a = the amount of 4.5% mixture needed
Let b = the amount of 9.75% mixture needed
In words:
(alcohol in the two mixtures) / (total mixture) = 7.25%
%28.045a+%2B+.0975b%29+%2F+%28a+%2B+b%29+=+.0725
also given is
a+%2B+b+=+300
b+=+300+-+a
%28.045a+%2B+.0975%28300+-+a%29%29+%2F+300+=+.0725
%28.045a+%2B+29.25+-+.0975a%29+%2F+300+=+.0725
+.045a+%2B+29.25+-+.0975a+=+21.75
-.0525a+=+-7.5
a+=+142.857 liters answer
b+=+300+-+142.857
b+=+157.143 liters answer
check:
%28.045a+%2B+.0975b%29+%2F+%28a+%2B+b%29+=+.0725
%28.045%2A142.857+%2B+.0975%2A157.143%29+%2F+300+=+.0725
%286.429+%2B+15.321%29+%2F+300+=+.0725
21.75+%2F+300+=+.0725
21.75+=+21.75
OK