Find all School-related info fast with the new School-Specific MBA Forum
Learn more about the recent changes... close

It is currently 22 May 2013, 10:19
Customize  |  Hide

Search
Register
New posts
Unanswered

Is |x| < 1 ?

  Question banks Downloads My Bookmarks Reviews  
  Oldest Best Reply
Search for:
 
Print view
First unread post
Author Message
TAGS:
Manager
Manager
Joined: 10 Apr 2012
Posts: 88
Followers: 0

Kudos [?]: 8 [0], given: 116

GMAT ToolKit User CAT Tests
Is |x| < 1 ? [#permalink] New post 13 Feb 2013, 05:55
00:00

Question Stats:

71% (01:34) correct 28% (01:00) wrong based on 1 sessions
Is |x| < 1 ?

(1) x^4 -1 > 0

(2) 1/ (1-|x|) > 0

Could any one tell me the approach without testing the numbers ?

thanks!
[Reveal] Spoiler: OA

Last edited by Bunuel on 13 Feb 2013, 10:16, edited 2 times in total.
Edited the question.
2 KUDOS received
Senior Manager
Senior Manager
Joined: 24 Aug 2009
Posts: 282
Schools: Harvard, Columbia, Stern, Booth, LSB,
Followers: 2

Kudos [?]: 138 [2] , given: 217

Re: Is |x|<1 [#permalink] New post 13 Feb 2013, 06:13
2
This post received
KUDOS
Is |x|<1
1)X^4 -1 >0
2) 1/ 1-|x| >0

Question stem asks whether Is -1<x<1
Statement 1-X^4 -1 >0 ------>X^4 >1----> In order for this to be true x must be either greater than 1 or less than -1 i.e. x>1 or x<-1
In other words x does not fall in the range -1 to 1
Thus Sufficient

Statement 2 - 1/ 1-|x| >0
LHS is greater than 0 i.e. (any Positive number). Becuase the Numerator is positive Denominator has to be positive as well
Denominator = 1- |x|
In order to keep the Denominator positive, the Absolute value of x < Absolute value of 1
i.e. x range between -1 to 1.
Thus sufficient.

I hope this explanation helps.
By the way, this is a very POOR quality question as both options give two different answers.

Fame

guerrero25 wrote:
Thanks for the explanation , Can we not have consistent answers to conclude that 1 & 2 independently are true?
Please clarify ..

Hi Guerrero,

That's possible logically but GMAT does not consider the same PRUDENT as you can observe that none of OG questions has two different answers.

Fame
_________________

If you like my Question/Explanation or the contribution, Kindly appreciate by pressing KUDOS.
Kudos always maximizes GMATCLUB worth -Game Theory


Last edited by fameatop on 13 Feb 2013, 10:15, edited 2 times in total.
1 KUDOS received
Manager
Manager
Joined: 10 Apr 2012
Posts: 88
Followers: 0

Kudos [?]: 8 [1] , given: 116

GMAT ToolKit User CAT Tests
Re: Is |x|<1 [#permalink] New post 13 Feb 2013, 07:37
1
This post received
KUDOS
fameatop wrote:
Is |x|<1
1)X^4 -1 >0
2) 1/ 1-|x| >0

Question stem asks whether Is -1<x<1
Statement 1-X^4 -1 >0 ------>X^4 >1----> In order for this to be true x must be either greater than 1 or less than -1 i.e. x>1 or x<-1
In other words x does not fall in the range -1 to 1
Thus Sufficient

Statement 2 - 1/ 1-|x| >0
LHS is greater than 0 i.e. (any Positive number). Becuase the Numerator is positive Denominator has to be positive as well
Denominator = 1- |x|
In order to keep the Denominator positive, the Absolute value of x < Absolute value of 1
i.e. x range between -1 to 1.
Thus sufficient.

I hope this explanation helps.
By the way, this is a very POOR quality question as both options give two different answers.

Fame


Thanks for the explanation , Can we not have consistent answers to conclude that 1 & 2 independently are true?

1) False for all the conditions ( taking |2| & |-2| both satisfy the condition )


2) True for all the conditions ( Taking |-1/2| & |-1/2| )

Please clarify ..
SVP
SVP
User avatar
Joined: 01 Sep 2010
Posts: 1745
Followers: 55

Kudos [?]: 575 [0], given: 467

GMAT Tests User
Top Member of the Month
Re: Is |x|<1 [#permalink] New post 13 Feb 2013, 08:02
fameatop wrote:
Is |x|<1
1)X^4 -1 >0
2) 1/ 1-|x| >0

Question stem asks whether Is -1<x<1
Statement 1-X^4 -1 >0 ------>X^4 >1----> In order for this to be true x must be either greater than 1 or less than -1 i.e. x>1 or x<-1
In other words x does not fall in the range -1 to 1
Thus Sufficient

Statement 2 - 1/ 1-|x| >0
LHS is greater than 0 i.e. (any Positive number). Becuase the Numerator is positive Denominator has to be positive as well
Denominator = 1- |x|
In order to keep the Denominator positive, the Absolute value of x < Absolute value of 1
i.e. x range between -1 to 1.
Thus sufficient.

I hope this explanation helps.
By the way, this is a very POOR quality question as both options give two different answers.

Fame



I agree with you .............
_________________

KUDOS is the good manner to help the entire community.

Re: Is |x|<1   [#permalink] 13 Feb 2013, 08:02
    Similar topics Author Replies Last post
Similar
Topics:
 New posts Is |x|<1? guest 1 19 Aug 2004, 09:30
New posts EXPERTS_POSTS_IN_THIS_TOPIC Is |x|<1? mosquitojoyride 6 23 Sep 2009, 17:26
Popular new posts 9 EXPERTS_POSTS_IN_THIS_TOPIC Is |x|<1? mn2010 30 28 Jul 2010, 03:56
Popular new posts 3 EXPERTS_POSTS_IN_THIS_TOPIC Is |x-1| < 1? devinawilliam83 10 12 Feb 2012, 21:49
This topic is locked, you cannot edit posts or make further replies. New EXPERTS_POSTS_IN_THIS_TOPIC Is |x| < 1? Aximili85 4 29 Aug 2012, 10:11
Display posts from previous: Sort by

Is |x| < 1 ?

  Question banks Downloads My Bookmarks Reviews  
Print view
First unread post

Moderators: Bunuel, VeritasPrepKarishma, IanStewart

Search for:


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com