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

It is currently 18 Apr 2014, 23:26

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

Is xy>0

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Retired Moderator
User avatar
Joined: 18 Jul 2008
Posts: 997
Followers: 8

Kudos [?]: 55 [0], given: 5

GMAT Tests User
Is xy>0 [#permalink] New post 02 Dec 2008, 08:17
Is xy>0

(1) x - y > - 2
(2) x - 2y < - 6


GUys, what's the easiest way to do this? I plugged in numbers and it started to get confusing, and blew past the 2 minutes.
Manager
Manager
Joined: 02 Nov 2008
Posts: 60
Followers: 1

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

Re: Is xy>0 [#permalink] New post 02 Dec 2008, 08:26
I get c

I subtract eq 2 from 1 and
Manager
Manager
Joined: 14 Oct 2008
Posts: 160
Followers: 1

Kudos [?]: 22 [0], given: 0

Re: Is xy>0 [#permalink] New post 02 Dec 2008, 08:38
IMO C.

From 1st equation
x > y-2 ( not sufficient )

From 2nd equation
x < 2y-6 ( not sufficient)

Combining :
(y-2) < x < (2y-6)

hence y-2 < 2y-6
y > 4

Substituting the value in 1st equations we see that x.y is always positive

we can also check by substituting values in equation (y-2) < x < (2y-6)

Hence C.
Retired Moderator
User avatar
Joined: 18 Jul 2008
Posts: 997
Followers: 8

Kudos [?]: 55 [0], given: 5

GMAT Tests User
Re: Is xy>0 [#permalink] New post 02 Dec 2008, 10:35
But to solve for A and also B independently, you guys plugged in numbers?
SVP
SVP
Joined: 17 Jun 2008
Posts: 1580
Followers: 10

Kudos [?]: 167 [0], given: 0

GMAT Tests User
Re: Is xy>0 [#permalink] New post 02 Dec 2008, 11:27
Alternatively, draw the graph of the two inequalities and find out the common area. The common area will be in quadrant A and hence xy > 0 only when both the inequalities are considered.
Manager
Manager
Joined: 14 Oct 2008
Posts: 160
Followers: 1

Kudos [?]: 22 [0], given: 0

Re: Is xy>0 [#permalink] New post 02 Dec 2008, 16:00
bigfernhead wrote:
But to solve for A and also B independently, you guys plugged in numbers?


Yes I had plugged in numbers individually in both statements .....
Senior Manager
Senior Manager
Joined: 05 Jun 2008
Posts: 313
Followers: 2

Kudos [?]: 15 [0], given: 0

GMAT Tests User
Re: Is xy>0 [#permalink] New post 03 Dec 2008, 05:46
bigfernhead wrote:
Is xy>0

(1) x - y > - 2
(2) x - 2y < - 6


GUys, what's the easiest way to do this? I plugged in numbers and it started to get confusing, and blew past the 2 minutes.


Stem 1 -Insuff
Stemm 2 - InSuff
Both Put together are suff, Lts see
After Subst 2 from 1
x - y -x + 2y > - 2 + 6
y> 4 after puting this value in 1
X>2, which means XY>8
Re: Is xy>0   [#permalink] 03 Dec 2008, 05:46
    Similar topics Author Replies Last post
Similar
Topics:
New posts If xyz > 0, is x > 0? (1) xy > 0 (2) xz > 0 TeHCM 7 17 Dec 2005, 22:49
New posts is x+y > 0? sandy007 6 22 Jan 2006, 22:14
New posts DS- Is XY > 0 tarek99 3 21 Nov 2007, 15:25
New posts Is xy > 0 ? jackychamp 4 02 Jan 2009, 19:11
New posts 1 Experts publish their posts in the topic Is xy > 0? study 7 16 Nov 2009, 13:27
Display posts from previous: Sort by

Is xy>0

  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®.