• Board contributors include instructors with "800" GMAT scores.
  • 95% of posts have replies within 24 hours.
  • Join for discounts with 800score, VeritasPrep and ManhattanGMAT


FAQ  - Register  - Search - Login 

All times are UTC - 7 hours




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: GMAT Algebra (Data Sufficiency)
PostPosted: Tue Oct 20, 2009 5:44 pm 
Offline

Joined: Sun Apr 19, 2009 6:56 pm
Posts: 32
Is k^2 + k - 2 > 0 ?

(1) k is greater than zero
(2) k is an even integer

why exactly is it justified to go from asking whether the inequality equation is greater than zero to setting k = to 0? and assuming the factors are
relevant? It seems to me that it\'s a bit of a stretch.


Top
 Profile  
 
 Post subject: Re: Test 3, Question 33
PostPosted: Tue Oct 20, 2009 5:49 pm 
Offline
User avatar

Joined: Mon Apr 06, 2009 5:44 pm
Posts: 81
The question asks if the equation is greater than zero, not if its equal to zero. There is a distinction.
For example, if we factor the left hand side of the equation we have (k+2)(k-1) = 0 so if k is equal to 1 or , -2 the equation is equal to zero. However, in order for the equation to be greater than zero, k cannot be 1 or -2. Those are not the solutions to (k+2)(k-1) > 0.


Top
 Profile  
 
 Post subject: Re: Test 3, Question 33
PostPosted: Sun Apr 18, 2010 4:49 am 
Offline
User avatar

Joined: Fri Apr 09, 2010 2:11 pm
Posts: 453
It can be usefull to draw a number line for better comprehension:
Image
Please, remember that k² + k – 2 = 0 when k = -2 or k = 1.
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: Google [Bot] and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Template made by DEVPPL -
phpBB SEO
 
GMAT(TM) and GMAT CAT (TM) are registered trademarks of the Graduate Management Admission Council(TM). The Graduate Management Admission Council(TM) does not endorse, nor is affiliated in any way with the owner or any content of this site.