SOLUTION: A mixture of 7% disinfectant solution is to be made from 8% and 5% disinfectant solutions. How much of each solution should be used if 18 gallons of 7% solution are needed? You

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: A mixture of 7% disinfectant solution is to be made from 8% and 5% disinfectant solutions. How much of each solution should be used if 18 gallons of 7% solution are needed? You       Log On


   



Question 1095260: A mixture of 7% disinfectant solution is to be made from 8% and 5% disinfectant solutions. How much of each solution should be used if 18 gallons of 7% solution are needed?
You need ( ) gallons of 8% solution and ( ) gallons of 5% solution.

Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
0.08x + 0.05(18-x) = 0.07(18)
0.08x + 0.9 - 0.05x = 1.26
0.03x = 0.36
x = 12
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You need ( 12 ) gallons of 8% solution and ( 6 ) gallons of 5% solution