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
 

If Company M ordered a total of 50 computers and printers

Author Message
kourakis
 Post subject: If Company M ordered a total of 50 computers and printers
 Post Posted: Sun Aug 28, 2011 11:42 pm 
Offline
Students


Posts: 8
If Company M ordered a total of 50 computers and printers and Company N ordered a total of 60 computers and printers, how many printers did company M order?

(1) Company M and Company N ordered the same number of computers

(2) Company N ordered 10 more printers than Company M.

OA is E.

Here is my solution (initially chose C, because I did not solve the equations). Is there another way of approaching this problem? Thanks.

Let X=computers of M, Y=printers of M, Z=computers of N, T=printers of N

Looking for T

Facts: X+Y=50 ; Z+T=60

(1) X=Z ; This means that X+Y=50, Z+T=60. Could subtract equations and get that T-Y=10. INSUFFICIENT (know the relative difference, but not the exact #)

(2) Basically, this is the same equation as in (1) -- T-Y=10. No extra relationships so that we can calculate T or Y. INSUFFICIENT.

(1)^(2) INSUFFICIENT, since they are the same equations
Top 
RonPurewal
 Post subject: Re: If Company M ordered a total of 50 computers and printers
 Post Posted: Sat Sep 03, 2011 9:16 pm 
Offline
ManhattanGMAT Staff


Posts: 7146
kourakis wrote:
Is there another way of approaching this problem? Thanks.


as in the case of many algebraic problems, you can also pick numbers. since it's a data sufficiency problem, the goal is to try to get multiple numbers that satisfy the statements, thereby proving them insufficient. (if you can only find one number or set of numbers that satisfies the given constraints, then you pick “sufficient”.)

here are some choices of numbers:

* both companies order 40 computer; M orders 10 printers; N orders 20 printers

* both companies order 1 computer; M orders 49 printers; N orders 59 printers

these choices satisfy both statements, so both statements together are still insufficient -- therefore (e)
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 2 posts ] 





Who is online

Users browsing this forum: No registered users and 1 guest

 
 

 
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: