Find all School-related info fast with the new School-Specific MBA Forum

It is currently 22 Oct 2014, 05:04

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If xyz no= 0, is x (y + z) >= 0? (1) | y + z |=| y| +| z|

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 20 Mar 2005
Posts: 170
Followers: 2

Kudos [?]: 12 [0], given: 0

If xyz no= 0, is x (y + z) >= 0? (1) | y + z |=| y| +| z| [#permalink] New post 16 Oct 2007, 02:19
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
If xyz no= 0, is x (y + z) >= 0?
(1) | y + z |=| y| +| z|
(2)| x + y| =| x |+ |y|
SVP
SVP
User avatar
Joined: 01 May 2006
Posts: 1814
Followers: 8

Kudos [?]: 91 [0], given: 0

 [#permalink] New post 16 Oct 2007, 02:34
(C) for me :)

x (y + z) >= 0?
<=> sign(x) = sign(x+z) ?

Stat 1
|y + z|=|y| +|z|
<=> sign(y) = sign(z) = sign(x+z)

Nothing about the sign of x.

INSUFF.

Stat 2
|x + y| =|x|+ |y|
<=> sign(x) = sign(y) = sign(x+y)

Nothing about the sign of y+z.

INSUFF.

Both 1 and 2
We have :
o sign(y) = sign(z) = sign(y+z)
o sign(x) = sign(y) = sign(x+y)

So,
sign(x) = sign(y+z) thus x*(y+z) >= 0

SUFF.
SVP
SVP
User avatar
Joined: 01 May 2006
Posts: 1814
Followers: 8

Kudos [?]: 91 [0], given: 0

 [#permalink] New post 16 Oct 2007, 03:28
OlgaN wrote:
I am confused with this question, because if we are asked >=, and we can prove >, but we still do not know about =, should we think that we definitely know the answer?
Thus either C or E.


Well, I understand your point :)

But here, it cannot equal 0 :).... As the signs of x, y and z are the same and they are different from 0. :)

So it is more > than possibly = :)
SVP
SVP
User avatar
Joined: 01 May 2006
Posts: 1814
Followers: 8

Kudos [?]: 91 [0], given: 0

 [#permalink] New post 16 Oct 2007, 04:05
OlgaN wrote:
Fig wrote:
OlgaN wrote:
I am confused with this question, because if we are asked >=, and we can prove >, but we still do not know about =, should we think that we definitely know the answer?
Thus either C or E.


Well, I understand your point :)

But here, it cannot equal 0 :).... As the signs of x, y and z are the same and they are different from 0. :)

So it is more > than possibly = :)


Agree, thanks. Those brutal DS questions - they make me to think!!!!!


It would not be the last one like this ;)
  [#permalink] 16 Oct 2007, 04:05
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic Is x(y/z) > 0? sananoor 7 29 Dec 2012, 07:51
29 Experts publish their posts in the topic If x+y+z > 0, is z > 1 ? eddyed911 13 05 Feb 2011, 08:33
If xyz is not 0, is x (y + z) >= 0? (1)|y+z|=|y|+|z| minnu 2 13 Sep 2007, 01:11
xyz <> 0, is x (y + z) = 0? (1) y + z = y + z (2) x + yezz 2 22 Oct 2006, 15:48
xyz <> 0, is x (y + z) = 0? (1) y + z = y + z (2) x + chunjuwu 7 21 Jan 2005, 09:18
Display posts from previous: Sort by

If xyz no= 0, is x (y + z) >= 0? (1) | y + z |=| y| +| z|

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| 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®.