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Source: — Data Sufficiency |

by vineeshp » Sun Jul 24, 2011 7:09 am
Can you post your method and solution that helps you with A? Maybe then we can see if it works.
Vineesh,
Just telling you what I know and think. I am not the expert. :)
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by gmat25 » Sun Jul 24, 2011 7:36 am
vineeshp wrote:Can you post your method and solution that helps you with A? Maybe then we can see if it works.
Well i tried the cases, for Op A, if p = r, then i replaced r with p in the given question. first of all if u notice sign play no role here as both sides will gonna have same sign. That means the only cases u need to check are

case 1:-- r = p > 1

case 2:-- 0 < r = p < 1

In both these cases i find the eq'n holds true hence Op A
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by Frankenstein » Sun Jul 24, 2011 8:18 am
gmat25 wrote:
vineeshp wrote:Can you post your method and solution that helps you with A? Maybe then we can see if it works.
Well i tried the cases, for Op A, if p = r, then i replaced r with p in the given question. first of all if u notice sign play no role here as both sides will gonna have same sign. That means the only cases u need to check are

case 1:-- r = p > 1

case 2:-- 0 < r = p < 1

In both these cases i find the eq'n holds true hence Op A
Hi,
Why didn't you consider the case r<0? For r<0, the sign of inequality changes because 1/r - 1/(r^2+2) = 2/r(r^2+2). It's sign depends on the sign of r.
If you have considered only r>0, that means you are in fact considering statement(2) as well. Hence, the answer should be C.
Cheers!

Things are not what they appear to be... nor are they otherwise
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by Ozlemg » Sun Jul 24, 2011 9:41 am
It is C.
Thank you Frankestain...You are cut out for maths.
And you are my e-gmat-idol hehe :)
The more you suffer before the test, the less you will do so in the test! :)
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by gmat25 » Sun Jul 24, 2011 10:45 am
Frankenstein wrote:
gmat25 wrote:
vineeshp wrote:Can you post your method and solution that helps you with A? Maybe then we can see if it works.
Well i tried the cases, for Op A, if p = r, then i replaced r with p in the given question. first of all if u notice sign play no role here as both sides will gonna have same sign. That means the only cases u need to check are

case 1:-- r = p > 1

case 2:-- 0 < r = p < 1

In both these cases i find the eq'n holds true hence Op A
Hi,
Why didn't you consider the case r<0? For r<0, the sign of inequality changes because 1/r - 1/(r^2+2) = 2/r(r^2+2). It's sign depends on the sign of r.
If you have considered only r>0, that means you are in fact considering statement(2) as well. Hence, the answer should be C.
I took r < 0 as case earlier but unfortunately made a silly mistake...thanks
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