SOLUTION: Can you help me with this word problem? A mechanic has 30 pints of an antifreeze-and-water solution that is 80% antifreeze. How any pints of water should be added to make a solutio

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Question 751662: Can you help me with this word problem? A mechanic has 30 pints of an antifreeze-and-water solution that is 80% antifreeze. How any pints of water should be added to make a solution that is 60% antifreeze?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+.8%2A30+=+24+ pints of antifreeze in 80% solution
Let +w+ = pints of water to be added
to make solution 60% antifreeze
---------------
+24+%2F+%28+30+%2B+w+%29+=+.6+
+24+=+.6%2A%28+30+%2B+w+%29+
+24+=+18+%2B+.6w+
+.6w+=+6+
+w+=+10+
10 pints of waters needs to be added
check:
+24+%2F+%28+30+%2B+w+%29+=+.6+
+24+%2F+%28+30+%2B+10+%29+=+.6+
+24+%2F+40+=+.6+
+24+=+.6%2A40+
+24+=+24+
OK