Math questions from any Manhattan Prep GMAT Computer Adaptive Test.
Anne1276
 
 

If x is not equal to 0, is |x| less than

by Anne1276 Sun Jun 17, 2007 2:52 pm

* I understand the rephrase and why this has to be true: -1 < x < 1
* BUT, I don't understand the manipulations of statement #1. Can you please help me understand:
o (1) INSUFFICIENT: If x > 0, this statement tells us that x > x/x or x > 1. If x < 0, this
statement tells us that x > x/-x or x > -1. This is not enough to tell us if -1 < x < 1.

THANKS!
Anne1276
 
 

Original Problem

by Anne1276 Mon Jun 18, 2007 1:30 pm

If x is not equal to 0, is |x| less than 1?

(1) x / |x| < x

(2) |x| > x
StaceyKoprince
ManhattanGMAT Staff
 
Posts: 9360
Joined: Wed Oct 19, 2005 9:05 am
Location: Montreal
 

by StaceyKoprince Tue Jun 19, 2007 2:43 am

Hi, please remember to cite the name of the company that produced this test (even if it's us!).
Stacey Koprince
Instructor
Director, Content & Curriculum
ManhattanPrep
Anne1276
 
 

by Anne1276 Tue Jun 19, 2007 7:16 am

MGMAT CAT 1 question 22:

If x is not equal to 0, is |x| less than 1?

(1) x/|x| < x

(2) |x| > x
StaceyKoprince
ManhattanGMAT Staff
 
Posts: 9360
Joined: Wed Oct 19, 2005 9:05 am
Location: Montreal
 

MGMAT CAT DS

by StaceyKoprince Thu Jun 21, 2007 5:15 pm

If x is not equal to 0, is |x| less than 1?

(1) x/|x| < x

(2) |x| > x



The manipulations for statement 1 have to do with the rule that when you multiply or divide an inequality by a negative number, you have to switch the direction of the sign. This is an important rule to remember for difficult questions (and they like to use it on DS in particular).

Take a look again and see if you can figure out what's going on based upon the above statement - I'd like you to be able to work through this one out on your own if you can b/c you'll remember it better for the test if you can do so. But come back and let us know if you still have questions.
Stacey Koprince
Instructor
Director, Content & Curriculum
ManhattanPrep
Anne1276
 
 

by Anne1276 Thu Jun 21, 2007 5:58 pm

Ok, I understand now. Thanks!