SOLUTION: The ratio of the length of ribbon c to the length of ribbon d is 3:1. A length of 6 cm is cut off from ribbon c. What length must be cut off from ribbon d so that the ratio of the

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: The ratio of the length of ribbon c to the length of ribbon d is 3:1. A length of 6 cm is cut off from ribbon c. What length must be cut off from ribbon d so that the ratio of the       Log On


   

Question 1095594: The ratio of the length of ribbon c to the length of ribbon d is 3:1. A length of 6 cm is cut off from ribbon c. What length must be cut off from ribbon d so that the ratio of the length of ribbon d remains the same as before.
Answer by josgarithmetic(39615) About Me  (Show Source):
You can put this solution on YOUR website!
c%2Fd=3%2F1=%28c-6%29%2F%28d-x%29
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system%28c%2Fd=3%2Cand%2C%28c-6%29%2F%28d-x%29=3%29

c=3d
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c-6=3d-3x
3d-6=3d-3x
-6=-3x
highlight%28x=2%29



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simple examples to check result of x=2.
c=15, d=5;
%2815-6%29%2F%285-2%29=9%2F3=3
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c=21, d=7;
%2821-6%29%2F%287-2%29=15%2F5=3
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c=45, d=15
%2845-6%29%2F%2815-2%29=39%2F13=3