SOLUTION: Naomi is making a cleaning solution that is 15% bleach. She has 2 gallons of 40% bleach solution currently to which she will add pure water (0% bleach) to make her cleaning soluti

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: Naomi is making a cleaning solution that is 15% bleach. She has 2 gallons of 40% bleach solution currently to which she will add pure water (0% bleach) to make her cleaning soluti      Log On

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Question 846757: Naomi is making a cleaning solution that is 15% bleach. She has 2 gallons of 40% bleach solution currently to which she will add pure water (0% bleach) to make her cleaning solution. How many gallons of water does she need to add?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +w+ = gallons of water she must add
+.4%2A2+=+.8+ = gallons of bleach in 40% solution
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+.8+%2F+%28+2+%2B+w+%29+=+.15+
+.8+=+.15%2A%28+2+%2B+w+%29+
+.8+=+.3+%2B+.15w+
+.15w+=+.5+
+w+=+3.333+
She needs to add 3 and 1/3 gallons of water
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check:
+.8+%2F+%28+2+%2B+w+%29+=+.15+
+.8+%2F+%28+2+%2B+3.333+%29+=+.15+
+.8+=+.15%2A5.333+
+.8+=+.8+
OK