Inequality

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Inequality

by jayanti » Wed Aug 17, 2011 1:11 am
if ab≠ 0 is (a-b/((a^-1)-(b^-1))^-1> a+b

1. IaI >IbI
2. a<b

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by GmatKiss » Wed Aug 17, 2011 5:41 am
jayanti wrote:if ab≠ 0 is (a-b/((a^-1)-(b^-1))^-1> a+b

1. IaI >IbI
2. a<b
IMO:D

Please let me know if this is correct!

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by krishnasty » Wed Aug 17, 2011 6:07 am
Can u pls explain how did u arrive at the conclusion?
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by Frankenstein » Wed Aug 17, 2011 6:43 am
jayanti wrote:if ab≠ 0 is (a-b/((a^-1)-(b^-1))^-1> a+b

1. IaI >IbI
2. a<b
Hi,
If the question is [(a-b)/((1/a)-(1/b))]^-1 > a+b, my solution:
((1/a)-(1/b))/(a-b) = -1/ab
So, we need to check Is -1/ab > a+b ?
From(1):
a=-1,b=-1/2 -> -1/ab = -2, a+b = -1.5. So, -1/ab < a+b
a=-1,b= 1/2 -> -1/ab = 2, a+b = -0.5. So, -1/ab > a+b
Not sufficient

From(2):
Use the same set
Not sufficient

Both (1) and (2): Use the same set.
Not sufficient

Hence, E
Cheers!

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by jayanti » Wed Aug 17, 2011 10:43 am
Hi, I don't know how the spoiler got in, the right answer is E.

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by jayanti » Wed Aug 17, 2011 11:24 am
Hi Frank, Is there any other way other than putting in the values.