SOLUTION: In a certain town, the ratio of children to adults is 3 to 7. What percentage of the town's population is adults? I took 3 divided by 7 to get approximately 43% and then subtracte

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: In a certain town, the ratio of children to adults is 3 to 7. What percentage of the town's population is adults? I took 3 divided by 7 to get approximately 43% and then subtracte      Log On


   

Question 442746: In a certain town, the ratio of children to adults is 3 to 7. What percentage of the town's population is adults?
I took 3 divided by 7 to get approximately 43% and then subtracted that from 100 percent. But the answer is 70%. Why??
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
In a certain town, the ratio of children to adults is 3 to 7. What percentage of the town's population is adults?
I took 3 divided by 7 to get approximately 43% and then subtracted that from 100 percent. But the answer is 70%. Why??
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3:7 is the same as 3x:7x
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Equation:
3x + 7x = 100%
10x = 100%
x = 10%
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% of children = 3x = 30%
% of adults = 7x = 70%
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Cheers,
Stan H.