Register    Login    Search    Rss Feeds

Forums Home » Ask An Instructor » GMAT Math » GMAT Prep Math


 Page 1 of 1 [ 2 posts ] 



  Print view Print view Previous topic Previous topic | Next topic Next topic
 

OG PS-D14

Author Message
Guest
 Post subject: OG PS-D14
 Post Posted: Fri Jan 02, 2009 6:15 pm 
i am working on a problem in the official guide book and i am confused about this questions.
A Venn Diagram is needed for this problem and in the solutions, it does not include the number in the shared part of the diagram when adding up the total.

Can someone explain why?
Top 
RonPurewal
 Post subject:
 Post Posted: Fri Jan 09, 2009 6:00 am 
Offline
ManhattanGMAT Staff


Posts: 7146
that's part of the quantity designated "x" in the problem. if you added it to x, you would actually be double-counting the shared region.

note: these sorts of problems are the best endorsement for our tried-and-true Double Set Matrix (the device we use to attack overlapping sets problems). when you use the double set matrix, each possibility gets a separate square in the grid, and you don't have to worry anywhere near as much about things like double-counts.
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 2 posts ] 





Who is online

Users browsing this forum: No registered users 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: