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Ratio Problem

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Ratio Problem

by tanyasethi » Mon Jul 11, 2011 1:17 pm
If the ratio of 2 a to b is 8 times the ratio of b to a , then could be
* 1/4
* 1/2
* 2
* 1
* 4

Could someone please explain this problem to me. The answer is 1/2.
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by kevincanspain » Mon Jul 11, 2011 1:48 pm
tanyasethi wrote:If the ratio of 2 a to b is 8 times the ratio of b to a , then could be
* 1/4
* 1/2
* 2
* 1
* 4

Could someone please explain this problem to me. The answer is 1/2.
Note that the ratio of a to b can be written as a:b or a/b

Thus
2(a/b) = 8 (b/a)

2a^2 = 8b^2
a^2 = 4b^2

|a| = 2|b|

That's all I can say! Can you check the wording of the question?
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by tanyasethi » Mon Jul 11, 2011 2:00 pm
Sorry I made a mistake typing the question, it should be then b/a could be...

the correct question is
If the ratio of 2 a to b is 8 times the ratio of b to a , then b/a could be
* 1/4
* 1/2
* 2
* 1
* 4

Sorry again! My bad! Will be more careful the next time around!
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by goalevan » Mon Jul 11, 2011 2:55 pm
2a/b = 8b/a
2a^2 = 8b^2
a^2 = 4b^2
(a/b)^2 = 4
a/b = +2 or -2

Therefore 1/(a/b) = b/a could be 1/(2) or 1/(-2)

B
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by MBA.Aspirant » Tue Jul 12, 2011 2:00 am
tanyasethi wrote: If the ratio of 2 a to b is 8 times the ratio of b to a , then b/a could be
* 1/4
* 1/2
* 2
* 1
* 4
2a/b = 8b/a

2a^2 = 8b^2

a^2 = 4b^2

a = 2b

b/a = 1/2
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by tanyasethi » Tue Jul 12, 2011 12:13 pm
Thanks a ton! :)
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