More Number Properties

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More Number Properties

by rosh26 » Sun Jun 22, 2008 5:48 pm
Thanks in advance...
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by ksh » Sun Jun 22, 2008 11:51 pm
Is x>0

Stem 1. a+b>0, a may be 0 or b may be then also valid. however when b=0, x can be more than 0 only in case a is positive, if a is negative x will be -ve. Insuff

Stem2. a-b>0 similarly this is also insuff

Hence. E

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by shilotilo » Mon Jun 23, 2008 6:35 pm
Hi,
Why not C?
I think the question stem translates finally into is minus b/a greater than 0 or , final translation, is b/a less than 0 (the minus key is not working in my keyboard)

Taking both the statements together, we get a, as well as b, is greater than 0. So b/a is greater than 0.

C answers the question, isn't that so? Or am I making a mistake somewhere?


Shilo

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by rosh26 » Sun Jun 29, 2008 5:37 pm
OA is E- can experts help?

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by gxliu » Mon Jun 30, 2008 7:04 am
AX+B=0, is X>0
1) A+B>0 (insufficient)
2)A-B>0 (insufficient)

Combined: A=4 and B = -2 which satisfies both statements, which leaves
x=1/2 which is >0

A=2 and B= 1, which satifies both statements, which
leaves X= -1/2 which is <0.

Answer is E.