is |x|=y-z ? 1. x+y=z 2. x<0 first we know that y-z=|x|, : DS Archive
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

It is currently 07 Dec 2016, 19:18
GMAT Club Tests

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

is |x|=y-z ? 1. x+y=z 2. x<0 first we know that y-z=|x|,

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Senior Manager
Senior Manager
User avatar
Joined: 31 Jul 2006
Posts: 440
Followers: 3

Kudos [?]: 44 [0], given: 0

is |x|=y-z ? 1. x+y=z 2. x<0 first we know that y-z=|x|, [#permalink]

Show Tags

New post 07 Oct 2006, 18:23
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

is |x|=y-z ?

1. x+y=z

2. x<0

first we know that y-z=|x|, so

-x=y-z
-x=y-z

from 1. we know that x=z-y, so -x=y-z, so why do we need 2?
Manager
Manager
avatar
Joined: 01 Oct 2006
Posts: 242
Followers: 1

Kudos [?]: 11 [0], given: 0

Re: DS: |x|=y-z [#permalink]

Show Tags

New post 07 Oct 2006, 19:31
Here is what I think.

Since |x| is positive, y-z should be greater than 0. (i)
Equation 1 says: x = z-y
if x is a positive number, z-y>0 i.e y-z < 0, which will contradict the conclusion in (i)
SVP
SVP
User avatar
Joined: 05 Jul 2006
Posts: 1681
Followers: 6

Kudos [?]: 297 [0], given: 48

GMAT ToolKit User
 [#permalink]

Show Tags

New post 08 Oct 2006, 01:24
is |x|=y-z ?

1. x+y=z

2. x<0

from stem

x = y-z x>=0 or x = z-y x<0

from one x = z-y ie x<0.....insuff

from two x<0 ...insuff

both insuff my answer is E
Senior Manager
Senior Manager
User avatar
Joined: 28 Aug 2006
Posts: 306
Followers: 13

Kudos [?]: 142 [0], given: 0

 [#permalink]

Show Tags

New post 08 Oct 2006, 09:30
It must be C.
Is |X| =Y-Z.

1: x+y =z
2+3 = 5 ie x=2 y=3 and z=5
These values will not satisfy |x|=y-z

-2+3 =1 i.e x=-2 y=3 and z=1
These values will satisfy |x|=y-z.

So 1 is not sufficient

2: x<0 Clearly alone not sufficient.

Let's combine both.

Since x<0, |x| =-x.------------(1)
given x+y= z
ie x=z-y
ie -x = y-z
ie |x| = y-z from (1)

So it is C
_________________

Averages Accelerated:Guide to solve Averages Quickly(with 10 practice problems)

Director
Director
avatar
Joined: 23 Jun 2005
Posts: 847
GMAT 1: 740 Q48 V42
Followers: 5

Kudos [?]: 66 [0], given: 1

 [#permalink]

Show Tags

New post 08 Oct 2006, 10:08
Another one for C.

I wasn't sure how to explain my answer till Cicerone did a great job of it.
Senior Manager
Senior Manager
User avatar
Joined: 30 Aug 2006
Posts: 374
Followers: 3

Kudos [?]: 64 [0], given: 0

 [#permalink]

Show Tags

New post 08 Oct 2006, 10:47
C

|x| = y - z

I) x + y = z
x = z - y

if x is negative |x| = y - z, however it may be positive & x = z - y

so we need II

II) x < 0
SVP
SVP
User avatar
Joined: 05 Jul 2006
Posts: 1681
Followers: 6

Kudos [?]: 297 [0], given: 48

GMAT ToolKit User
 [#permalink]

Show Tags

New post 08 Oct 2006, 11:37
I guess i ve a lot to learn and practise thanks everyone :lol:
  [#permalink] 08 Oct 2006, 11:37
Display posts from previous: Sort by

is |x|=y-z ? 1. x+y=z 2. x<0 first we know that y-z=|x|,

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.