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

It is currently 21 Sep 2014, 22:15

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 > 0, is x > 0? (1) xy > 0 (2) xz > 0

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
VP
VP
avatar
Joined: 06 Jun 2004
Posts: 1062
Location: CA
Followers: 2

Kudos [?]: 26 [0], given: 0

GMAT Tests User
If xyz > 0, is x > 0? (1) xy > 0 (2) xz > 0 [#permalink] New post 17 Dec 2005, 22:49
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 > 0, is x > 0?

(1) xy > 0
(2) xz > 0
Manager
Manager
avatar
Joined: 12 Nov 2005
Posts: 78
Followers: 1

Kudos [?]: 4 [0], given: 0

 [#permalink] New post 18 Dec 2005, 10:24
XYZ > 0

Statement I
XY >0
Implies X & Y are both Positive or Both negative.......Not sufficient

Statement II
XZ >0
Implies X & Z are both Positive or Both negative.......Not sufficient

Statement I & II
XY > 0
XZ > 0 From the main statement (XYZ > 0), This is possible only if all three are positive

Hence X>0 ........Answer is C
Director
Director
avatar
Joined: 17 Dec 2005
Posts: 555
Location: Germany
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 18 Dec 2005, 10:34
[i]Disagree..

xyz>0

(1) If xy>0, than both x and y have to be either negative or positive

(2) If xz>0, than both x and z have to be either positive or negative

=> Thus we do not know if all integers are positive or negative, therefore we have to choose E, because the product of three negative numbers is negative, that of three positive is positive.[/i]

Can't read yet, we don't talk about whether xyz> 0

Last edited by allabout on 19 Dec 2005, 06:42, edited 2 times in total.
Intern
Intern
avatar
Joined: 14 Dec 2005
Posts: 14
Followers: 0

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

 [#permalink] New post 19 Dec 2005, 05:57
If xy > 0 then z > 0
If xz > 0 then y > 0

If z > 0 and y > 0 then x > 0.

Hence C.
Director
Director
avatar
Joined: 17 Oct 2005
Posts: 941
Followers: 1

Kudos [?]: 30 [0], given: 0

GMAT Tests User
 [#permalink] New post 19 Dec 2005, 06:36
great question.

At first i chose E but now i see that C makes sense
Senior Manager
Senior Manager
avatar
Joined: 05 Oct 2005
Posts: 487
Followers: 1

Kudos [?]: 2 [0], given: 0

GMAT Tests User
Re: GMAT Prep - DS XYZ [#permalink] New post 19 Dec 2005, 10:40
TeHCM wrote:
If xyz > 0, is x > 0?

(1) xy > 0
(2) xz > 0


C..
possible arrangements

x y z
1) + + +
- - +

2) + + +
- + -

Only + + + is common to both, thus x>0
Senior Manager
Senior Manager
User avatar
Joined: 14 Apr 2005
Posts: 422
Location: India, Chennai
Followers: 1

Kudos [?]: 3 [0], given: 0

GMAT Tests User
Re: GMAT Prep - DS XYZ [#permalink] New post 20 Dec 2005, 04:27
TeHCM wrote:
If xyz > 0, is x > 0?

(1) xy > 0
(2) xz > 0


From 1 x could be +ve or -ve hence insuff.
From 2 x could still be + ve or -ve hence insuff.

Combining both. we get x^2yz > 0
or x (xyz) > 0
We are given that xyz > 0 which means x must be +ve to make
x(xyz) > 0. Hence C.
Senior Manager
Senior Manager
avatar
Joined: 11 Nov 2005
Posts: 336
Location: London
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 20 Dec 2005, 06:51
IMO C.

if xyz>0

1. xy>0, therefore either x y are positive or negative, not sufficient

however if xy are positive or negative, in any case, z is positive which satisfy the original statament.

2. xz >0 alone is insufficient to say x>0, but combined with the above observation (z>0) x must be positive. and the answer C.
  [#permalink] 20 Dec 2005, 06:51
    Similar topics Author Replies Last post
Similar
Topics:
5 If xyz > 0, is x > 0? (1) xy > 0 (2) xz > 0 DestinyChild 8 10 Jan 2010, 18:31
If xyz > 0, is x > 0? (1) xy > 0 (2) xz > 0 tarek99 5 31 Mar 2008, 11:43
Source: GMATPrep If xyz>0, is x > 0? (1) xy>0 (2) Hang Tuah 2 21 Sep 2007, 20:43
If x>y>z, is xz>0? 1) xy<0 2) yz>0 vivek123 5 19 Mar 2006, 06:02
If xyz > 0, is x>0? 1) xy> 0 2) xz>0 jlui4477 3 24 Feb 2006, 19:04
Display posts from previous: Sort by

If xyz > 0, is x > 0? (1) xy > 0 (2) xz > 0

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.