Register    Login    Search    Rss Feeds

Forums Home » Ask An Instructor » GMAT Math » Manhattan GMAT CAT Math


 Page 1 of 1 [ 4 posts ] 



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

Absolute Question -CAT exam 3A

Author Message
shantascherla
 Post subject: Absolute Question -CAT exam 3A
 Post Posted: Fri Apr 15, 2011 1:59 pm 
Offline
Course Students


Posts: 21
If a and b are integers, and |a| > |b|, is a · |b| < a – b?

(1) a < 0

(2) ab 0

OA e

The official explanation is pretty long - and if was wondering if there are any tricks that can help in resolving the question in 2-3 minutes
Top 
tim
 Post subject: Re: Absolute Question -CAT exam 3A
 Post Posted: Fri Apr 15, 2011 9:12 pm 
Offline
ManhattanGMAT Staff


Posts: 2183
Location: Southwest Airlines, seat 21C
sure - try plugging in numbers..

_________________
Tim Sanders
Manhattan GMAT Instructor
Top 
entebbe21
 Post subject: Re: Absolute Question -CAT exam 3A
 Post Posted: Thu Apr 28, 2011 2:06 am 
Offline
Students


Posts: 1
well, lets use numbers.

|a|>|b|
when a=-2, b = -1

a*|b|<a-b?

so,

-2*1<-2+1?
-2<-1 - YES.

when a=-2, b=1

-2*1<-2-1?
-2<-3?
NO.

so statement 1 is Ins.

st. 2:
a*b=0
so B is zero (A cannot be = 0 bc his distance from zero is bigger than b's distance |a|>|b|)

so:a*|b|<a-b?
0<a

we disregard stm.1 so a can be <>0
means - no answer here as well.


if we put both of them in:
i dont c why u cannot tell if

0<a when a<0. it will always be smaller than 0 what am i missing?
Top 
jnelson0612
 Post subject: Re: Absolute Question -CAT exam 3A
 Post Posted: Sat Apr 30, 2011 1:22 pm 
Online
ManhattanGMAT Staff


Posts: 1857
The problem is that statement 2 is written incorrectly.

It should actually read:

2) a*b > 0,
NOT a*b=0.

Check out this thread which has a lot of information about this problem: if-a-and-b-are-integers-and-a-b-is-a-b-a-b-t9437.html

_________________
Jamie Nelson
ManhattanGMAT Instructor
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 4 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: