SOLUTION: hi tutor,,please help me again for this question...2.how much pure alcohol must be added to a 12L of a 20% alcohol sulotion to make a solution that is 60% alcohol? thank you..

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: hi tutor,,please help me again for this question...2.how much pure alcohol must be added to a 12L of a 20% alcohol sulotion to make a solution that is 60% alcohol? thank you..      Log On

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Question 648054: hi tutor,,please help me again for this question...2.how much pure alcohol must be added to a 12L of a 20% alcohol sulotion to make a solution that is 60% alcohol?
thank you..

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +x+ = liters of pure alcohol to be added
+.2%2A12+=+2.4+ liters of pure alcohol in 20% solution
--------------
+%28+x+%2B+2.4+%29+%2F+%28+x+%2B+12+%29+=+.6+
+x+%2B+2.4+=+.6%2A%28+x+%2B+12+%29+
+x+%2B+2.4+=+.6x+%2B+7.2+
+.4x+=+7.2+-+2.4+
+.4x+=+4.8+
+x+=+12+
12 liters of pure alcohol need to be added
check:
+%28+x+%2B+2.4+%29+%2F+%28+x+%2B+12+%29+=+.6+
+%28+12+%2B+2.4+%29+%2F+%28+12+%2B+12+%29+=+.6+
+14.4+%2F+24+=+.6+
+14.4+=+.6%2A24+
+14.4+=+14.4+
OK