SOLUTION: Trevon wants to make a 40% acid solution. He has already poured 6 fl. oz. of a 20% acid solution into a beaker. How many fl. oz. of a 80% acid solution must he add to this to creat

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: Trevon wants to make a 40% acid solution. He has already poured 6 fl. oz. of a 20% acid solution into a beaker. How many fl. oz. of a 80% acid solution must he add to this to creat      Log On

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Question 653610: Trevon wants to make a 40% acid solution. He has already poured 6 fl. oz. of a 20% acid solution into a beaker. How many fl. oz. of a 80% acid solution must he add to this to create the desired mixture?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = fl oz of 80% solution needed
+.2%2A6+=+1.2+ fl oz of acid in 20% solution
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+%28+.8x+%2B+1.2+%29+%2F+%28+x+%2B+6+%29+=+.4+
+.8x+%2B+1.2+=+.4%2A%28+x+%2B+6+%29+
+.8x+%2B+1.2+=+.4x+%2B+2.4+
+.4x+=+1.2+
+x+=+3+
3 fl oz of 80% solution are needed
check:
+%28+.8%2A3+%2B+1.2+%29+%2F+%28+3+%2B+6+%29+=+.4+
+%28+2.4+%2B+1.2+%29+%2F+9+=+.4+
+3.6+%2F+9+=+.4+
+3.6+=+.4%2A9+
+3.6+=+3.6+
OK