NEW HERE? LEARN MORE
closeclose
Last visit was: 06 May 2024, 09:29 It is currently 06 May 2024, 09:29
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

DS - inequ

User avatar
domleon
Manager
Manager
Joined: 14 Jun 2007
Posts: 77
Own Kudos [?]: 75 [0]
Given Kudos: 0
Location: Vienna, Austria
Send PM
DS - inequ [#permalink] New post   02 Nov 2008, 03:36
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hide Show timer Statistics
guys
can you help me with this ... don´t have an OA!

cheers



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Data Sufficiency (DS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
scthakur
Director
Director
Joined: 17 Jun 2008
Posts: 614
Own Kudos [?]: 444 [0]
Given Kudos: 0
Send PM
Re: DS - inequ [#permalink] New post   02 Nov 2008, 04:17
E.

From stmt1: 7x - 2y > 0, x > 0 and y can be +ve or -ve.
From stmt2, x+y > 0 and again, y can be +ve or -ve.

Combining two also gives x > 0 with y having any values.
User avatar
amitdgr
Director
Director
Joined: 30 Jun 2008
Posts: 538
Own Kudos [?]: 2732 [0]
Given Kudos: 1
Send PM
Re: DS - inequ [#permalink] New post   02 Nov 2008, 07:05
scthakur wrote:
E.

From stmt1: 7x - 2y > 0, x > 0 and y can be +ve or -ve.
From stmt2, x+y > 0 and again, y can be +ve or -ve.

Combining two also gives x > 0 with y having any values.


can we not do the following ??

Combining the two statements .. we can solve the two inequalities as we solve simultaneous equations

eliminating x
a) 7x-2y >0 (stmt 1)
b) 7x+7y > 0 (stmt 2 * 7)

a-b => -9y > 0 or y<0

hence C

Am I doing anything wrong ?
User avatar
kman
Manager
Manager
Joined: 09 Jul 2008
Posts: 69
Own Kudos [?]: 854 [0]
Given Kudos: 1
Location: Dallas, TX
Concentration: Consulting, Product Management, Entrepreneurship
Schools:McCombs 2011
 Q50  V38
Send PM
Re: DS - inequ [#permalink] New post   02 Nov 2008, 07:33
amitdgr wrote:
scthakur wrote:
E.

From stmt1: 7x - 2y > 0, x > 0 and y can be +ve or -ve.
From stmt2, x+y > 0 and again, y can be +ve or -ve.

Combining two also gives x > 0 with y having any values.


can we not do the following ??

Combining the two statements .. we can solve the two inequalities as we solve simultaneous equations

eliminating x
a) 7x-2y >0 (stmt 1)
b) 7x+7y > 0 (stmt 2 * 7)

a-b => -9y > 0 or y<0

hence C

Am I doing anything wrong ?


I'll pick E.

stmt 1: y can be +ve or -ve
stmt 2: Just says -x < y. y can be -5 and x can 10. Or y can be 10 and x can be 5. Insuff
User avatar
scthakur
Director
Director
Joined: 17 Jun 2008
Posts: 614
Own Kudos [?]: 444 [0]
Given Kudos: 0
Send PM
Re: DS - inequ [#permalink] New post   03 Nov 2008, 00:29
amitdgr wrote:
can we not do the following ??

Combining the two statements .. we can solve the two inequalities as we solve simultaneous equations

eliminating x
a) 7x-2y >0 (stmt 1)
b) 7x+7y > 0 (stmt 2 * 7)

a-b => -9y > 0 or y<0

hence C

Am I doing anything wrong ?


Subtracting two inequalities is not correct all the time. For example, 2 > 0 and 3 > 0 but, (2-3) < 0. However, additions is ok.
User avatar
GODSPEED
Manager
Manager
Joined: 24 Sep 2008
Posts: 126
Own Kudos [?]: 1075 [0]
Given Kudos: 7
Schools:MIT / INSEAD / IIM - ABC
 Q48  V32
GPA: 3.6
Send PM
Re: DS - inequ [#permalink] New post   03 Nov 2008, 02:01
scthakur wrote:
amitdgr wrote:
can we not do the following ??

Combining the two statements .. we can solve the two inequalities as we solve simultaneous equations

eliminating x
a) 7x-2y >0 (stmt 1)
b) 7x+7y > 0 (stmt 2 * 7)

a-b => -9y > 0 or y<0

hence C

Am I doing anything wrong ?


Subtracting two inequalities is not correct all the time. For example, 2 > 0 and 3 > 0 but, (2-3) < 0. However, additions is ok.


My two cents, since we don't know wether y>0 or <0 so we can't do the substraction...as our friend explained using example: 2 > 0 and 3 > 0 but, (2-3) < 0.
User avatar
amitdgr
Director
Director
Joined: 30 Jun 2008
Posts: 538
Own Kudos [?]: 2732 [0]
Given Kudos: 1
Send PM
Re: DS - inequ [#permalink] New post   03 Nov 2008, 02:37
scthakur wrote:
amitdgr wrote:
can we not do the following ??

Combining the two statements .. we can solve the two inequalities as we solve simultaneous equations

eliminating x
a) 7x-2y >0 (stmt 1)
b) 7x+7y > 0 (stmt 2 * 7)

a-b => -9y > 0 or y<0

hence C

Am I doing anything wrong ?


Subtracting two inequalities is not correct all the time. For example, 2 > 0 and 3 > 0 but, (2-3) < 0. However, additions is ok.


Ok :) I get it ..... Is adding 2 inequalities fine ?
User avatar
scthakur
Director
Director
Joined: 17 Jun 2008
Posts: 614
Own Kudos [?]: 444 [1]
Given Kudos: 0
Send PM
Re: DS - inequ [#permalink] New post   03 Nov 2008, 02:49
1
Kudos
amitdgr wrote:
Ok :) I get it ..... Is adding 2 inequalities fine ?


Addition is the only thing that should be done on inequalities.

For example, a > 0, b > 0 and hence (a+b) > 0.
Alternatively, a < 0, b < 0 and hence (a+b) < 0.
User avatar
amitdgr
Director
Director
Joined: 30 Jun 2008
Posts: 538
Own Kudos [?]: 2732 [0]
Given Kudos: 1
Send PM
Re: DS - inequ [#permalink] New post   03 Nov 2008, 03:07
scthakur wrote:
amitdgr wrote:
Ok :) I get it ..... Is adding 2 inequalities fine ?


Addition is the only thing that should be done on inequalities.

For example, a > 0, b > 0 and hence (a+b) > 0.
Alternatively, a < 0, b < 0 and hence (a+b) < 0.


Thanks scthakur :) +1



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Data Sufficiency (DS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: DS - inequ [#permalink]
03 Nov 2008, 03:07
Moderators:
Bunuel
Math Expert
93057 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts
GMATBusters
GMAT Tutor
1904 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions