OG 11- 154 It is simple, but....

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OG 11- 154 It is simple, but....

by Megumi » Sun Dec 23, 2007 4:34 pm
Hi, I'm having a difficulty to understand the answer. If anybody could help me out, I would really appreciate it. Thanks,

Is X<0 ?

1) X^3(1-X^2)<0
2) X^2-1<0

I understand that from 1) we can get -1<X<0>1 and from 2) -1<X<1.
But together it only covers -1<X<0, it doesn't cover entire X<0, but still enough to answer C ?
Source: — Data Sufficiency |

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by StarDust845 » Mon Dec 24, 2007 8:56 am
I think the question asks is X < 0? The answer to the question is Yes. Because we can answer it, the answer must be C. The question didn't ask if x is -50 or something like that.

Calista.

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by rajivmatta » Sun Dec 30, 2007 11:51 am
IMO C

Fisrt condition satisfied by a variety of integers and fractions..I chose 2 and -0.25 for this test

Second condition however eliminates all positive integers and all integers for that matter..since square - 1 has to be negative..Therefore we are left with only negative fractions whose square is less than one (since +ve fractions will not satisfy one)..Therefore C

What is the OA?

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by rchadha7 » Sun Dec 30, 2007 12:52 pm
test
Last edited by rchadha7 on Sun Dec 30, 2007 12:58 pm, edited 1 time in total.

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by rchadha7 » Sun Dec 30, 2007 12:58 pm
1) x cube (1 - x sq) < 0
So (x cube) <0 And (1 - x sq) >0
x < 0 -1<x<1
Taking together -1<x<0 ----------------------------1
OR
So (x cube) > 0 .... and (1 - x sq) < 0
x > 0 -1>x>1
Taking together x>1--------------------------------2
For 1 x can be -ve or +ve

2) (x sq -1 ) < 0
-1<x<1 ---------------------------------------------3
For 2 x can be -ve or +ve
Taking 1,2,3 we can conclude x < 0 hence C