gmat prep inequalities/no. props

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Re: gmat prep inequalities/no. props

by chetanojha » Mon May 04, 2009 12:19 pm
a(b-c)=0 means question is asking is b=c? or b-c=0?

1. b-c=c-b
b+b=c+c ==> 2b=2c ==> b=c hence SUFFICIENT.

2. b/c = c/b
here c & b are either same signs or opposite signs.
In either case by cross multiplying b*b=c*c will be positive.
Hence b=c SUFFICIENT.

Hence D
vkb16 wrote:if a>0, b>0, c>0, is a(b-c)=0?

I. b-c = c-b
II. b/c = c/b

OA is D

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by vkb16 » Mon May 04, 2009 10:02 pm
thanks

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Re: gmat prep inequalities/no. props

by fruti_yum » Fri Aug 21, 2009 1:56 pm
vkb16 wrote:if a>0, b>0, c>0, is a(b-c)=0?

I. b-c = c-b
II. b/c = c/b

OA is D
Can someone elaborate on Statement 2?

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by uptowngirl92 » Fri Aug 21, 2009 6:23 pm
Guys I got the answer as A.
For stmt 2...we get b^2=c^2,,how is this suff,..?one of them can be -ive also..
Plese elaborate..

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by PAB2706 » Fri Aug 21, 2009 7:40 pm
yep i got A too...

statement 2 gives |b|=|c|

m i missing something?

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by iamjakekim » Fri Aug 21, 2009 8:10 pm
uptowngirl92 wrote:Guys I got the answer as A.
For stmt 2...we get b^2=c^2,,how is this suff,..?one of them can be -ive also..
Plese elaborate..

A/B/C are ALL POSITIVE. so we do not need to worry about (-b)^2 or something.

Think about it.

What is a POSITIVE number that can satisfy 3^2 = X^2

Obviously, it's 3.