Register    Login    Search    Rss Feeds

Forums Home » Ask An Instructor » GMAT Math » General Math Questions


 Page 1 of 1 [ 5 posts ] 



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

help pls!!!

Author Message
swapna.rajanish7
 Post subject: help pls!!!
 Post Posted: Fri Feb 26, 2010 9:37 pm 
Offline
Course Students


Posts: 13
A wire is cut into 3 equal parts. The resulting segments are then cut into 4,6 and 8 equal parts respectively. If each of the resulting segments has an inner length, what is the minimum length of the wire?

24
36
48
54
72

ans: e. Can some one explain??
Top 
jkandas
 Post subject: Re: help pls!!!
 Post Posted: Fri Feb 26, 2010 9:47 pm 
Offline
Course Students


Posts: 4
There could be a better approach for this...but at the first glance, I figured this will be tedious algebraically...so I started picking numbers...started from the middle...

48 - divided by 3 yields 16...but that is not divisible by 4, 6 and 8...
quickly going through the rest...only 72 gives the proper result

72/3 -> 24, which is then divisible by 4, 6 and 8...
Top 
Ben Ku
 Post subject: Re: help pls!!!
 Post Posted: Tue Mar 16, 2010 2:59 am 
Offline
ManhattanGMAT Staff


Posts: 819
Please cite the source (author) of this problem. We cannot reply unless a source is cited (and, if no source is cited, we will have to delete the post!). Thanks.

_________________
Ben Ku
Instructor
ManhattanGMAT
Top 
michael_shaunn
 Post subject: Re: help pls!!!
 Post Posted: Sat Apr 03, 2010 2:52 pm 
Offline
Forum Guests


Posts: 10
The question says that the wire was divided into three equal parts which in turn were divided into 4,6 and 8 parts respectively.
Now,can i say that each part after first division(after the original wire was cut) is divisible by 4,6 and 8.
Therefore to find the minimum length of the original wire...we have to find the minimum length of each equal part(after the original wire was cut) such that it is divisible by 4,6 and 8.....which is nothing but the l.c.m of 4,6 and 8.....whicih is 24.
So the minimum original length of the wire is 24*3=72.
Thanks.
Top 
dinesh19aug
 Post subject: Re: help pls!!!
 Post Posted: Fri Apr 09, 2010 2:46 pm 
Offline
Course Students


Posts: 37
Quote:
The question says that the wire was divided into three equal parts which in turn were divided into 4,6 and 8 parts respectively.
Now,can i say that each part after first division(after the original wire was cut) is divisible by 4,6 and 8.
Therefore to find the minimum length of the original wire...we have to find the minimum length of each equal part(after the original wire was cut) such that it is divisible by 4,6 and 8.....which is nothing but the l.c.m of 4,6 and 8.....whicih is 24.
So the minimum original length of the wire is 24*3=72.
Thanks.


The problem with this approach is 48 is also divisible by 48. and as we can see 6 is not a divisor of 16(one of the 3 equal part of 48).
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 5 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: