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Veritas DS -- confusing ??

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Veritas DS -- confusing ??

by saurabh_maths » Sun Jan 16, 2011 5:57 am
Is x^2 + y^2 > 100

1. 2xy < 100

2. (x+y)^2 > 200

This is Veritas question. I am quite confused with their solution.
Can you solve this and provide the explanation.
Experts please help me.

OA after some discussion.
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by anshumishra » Sun Jan 16, 2011 6:14 am
saurabh_maths wrote:Is x^2 + y^2 > 100

1. 2xy < 100

2. (x+y)^2 > 200

This is Veritas question. I am quite confused with their solution.
Can you solve this and provide the explanation.
Experts please help me.

OA after some discussion.
statement 1:
2xy < 100 => xy < 50 --- Not sufficient

statement 2 :

For any two numbers x and y : (x-y)^2 >= 0
=> x^2 + y^2 >= 2xy

(x+y)^2 > 200
=> x^2+y^2+2xy > 200
=> 2(x^2+y^2) > 200
=> x^2 + y^2 > 100 ---- Sufficient

Hence, B
Thanks
Anshu

(Every mistake is a lesson learned )
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by saurabh_maths » Sun Jan 16, 2011 7:36 am
Thanks Anshu ....

As per Veritas OA is C

I too came up with ans as B but veritas says that ans as C.
I could not understand their explanation and felt that they are wrong.

Here is Veritas explanation:
"In statement 2, it can be expanded to x^2+y^2+2xy > 200. Since no information is given about the value of 2xy, this statement is also insufficient to answer the question."

I too feel they are wrong.... and OA shd be B.

But would like to have a confirmation from a BTG Expert .
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by anshumishra » Sun Jan 16, 2011 8:31 am
saurabh_maths wrote:Thanks Anshu ....

As per Veritas OA is C

I too came up with ans as B but veritas says that ans as C.
I could not understand their explanation and felt that they are wrong.

Here is Veritas explanation:
"In statement 2, it can be expanded to x^2+y^2+2xy > 200. Since no information is given about the value of 2xy, this statement is also insufficient to answer the question."

I too feel they are wrong.... and OA shd be B.

But would like to have a confirmation from a BTG Expert .
Discussed here : https://www.beatthegmat.com/ds-question- ... 71832.html
Thanks
Anshu

(Every mistake is a lesson learned )
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