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OG Problem #192

Problem Solving — algebra and arithmetic
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by GHong14 » Sun Nov 28, 2010 3:41 pm
The ratio by volume, of soap to alcohol to water in a certain solution is 2:50:100. The solution will be altered so that the ratio of soap to alcohol is doubled while the ratio of soap to water is halved. if the altered solution will contain 100 cubic centimeters of alcohol, how many cubic centimeters of water will it contain?

Right answer is 800.

Anyone care to explain the steps to solve?!!?!?
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by Tani » Sun Nov 28, 2010 6:32 pm
Restate the proportion as x:25x:50x (where x = 2)

double soap to alcohol - we get 2x:25x:50x

Halve soap to water - we get 2x:25x:200X (water is now 100 times soap, not 50 times)

If alcohol (25x) = 100, x = 4.

200x - 800
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