BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

gmat prep -II ; If x is not equal to -y,

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1077
Joined: Mon Dec 13, 2010 1:44 am
Thanked: 118 times
Followed by:33 members
GMAT Score:710

gmat prep -II ; If x is not equal to -y,

by bblast » Thu Jul 21, 2011 2:03 am
If x is not equal to -y, is (x-y)/(x+y) > 1 ?


1> x>0

2> y<0

I could solve this by looking at the statements. But I would like to see whether we can algebraically reduce a solution.
E
Last edited by bblast on Thu Jul 21, 2011 4:01 am, edited 1 time in total.
Cheers !!

Quant 47-Striving for 50
Verbal 34-Striving for 40

My gmat journey :
https://www.beatthegmat.com/710-bblast-s ... 90735.html
My take on the GMAT RC :
https://www.beatthegmat.com/ways-to-bbla ... 90808.html
How to prepare before your MBA:
https://www.youtube.com/watch?v=upz46D7 ... TWBZF14TKW_
Top
Source: — Data Sufficiency |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Thu Jul 21, 2011 2:38 am
bblast wrote:If x is not equal to -y, is (x-y)/(x+y) > 1 ?
1> x>0
2> y<0
Consider the following two cases,
  • 1. x = 2 and y = -1 --> (x - y)/(x + y) = 3/1 = 3 > 1
    2. x = 2 and y = -3 --> (x - y)/(x + y) = 5/(-1) = -5 < 1
Both of the above cases satisfy both the statements but in one case the answer is to the main question is YES in other case it is NO. Hence, both statements together is not sufficient to answer the question.

The correct answer is E.
bblast wrote:...I would like to see whether we can algebraically reduce a solution.
The problem can be solved algebraically too, but in that case the solution will be a bit more time consuming.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 461
Joined: Tue May 10, 2011 9:09 am
Location: pune
Thanked: 36 times
Followed by:3 members

by amit2k9 » Thu Jul 21, 2011 2:44 am
you can condition this as per x and y as follows

add 1 to sides and you obtain

x/(x+y)> 1

subtract 1 from both sides and you obtain

y/(x+y) < 0

a. for x= 2 and y = -1|1 you have different results. Not sufficient.

b. for x= +|- 2 and y= -1 you have different results.not sufficient.

a+b

x=2 and y=-1 satisfies both the equations.
thus C it is.
For Understanding Sustainability,Green Businesses and Social Entrepreneurship visit -https://aamthoughts.blocked/
(Featured Best Green Site Worldwide-https://bloggers.com/green/popular/page2)
Top
User avatar
Legendary Member
Posts: 1077
Joined: Mon Dec 13, 2010 1:44 am
Thanked: 118 times
Followed by:33 members
GMAT Score:710

by bblast » Thu Jul 21, 2011 4:03 am
Thanks Anurag and Amit. Sorry I had erred in pasting the OA. {I was under the impression that I had got this one right-but realized after reading anurag's post and reviewing in detail}


Anurag- Could you please share with me an algebraic solution for this as well ?
Cheers !!

Quant 47-Striving for 50
Verbal 34-Striving for 40

My gmat journey :
https://www.beatthegmat.com/710-bblast-s ... 90735.html
My take on the GMAT RC :
https://www.beatthegmat.com/ways-to-bbla ... 90808.html
How to prepare before your MBA:
https://www.youtube.com/watch?v=upz46D7 ... TWBZF14TKW_
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Thu Jul 21, 2011 5:11 am
bblast wrote:Anurag- Could you please share with me an algebraic solution for this as well ?
For x > 0 and y < 0, (x - y) will be always positive.
But (x + y) may be positive or negative and accordingly (x - y)/(x + y) will be greater than 1 or less than 1.

If x > |y|, then (x - y)/(x + y) = (x + |y|)/(x - |y|) > 1
If x < |y|, then (x - y)/(x + y) = (x + |y|)/(x - |y|) < 0 < 1

Hence, both statements together is not sufficient.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
User avatar
Legendary Member
Posts: 1077
Joined: Mon Dec 13, 2010 1:44 am
Thanked: 118 times
Followed by:33 members
GMAT Score:710

by bblast » Thu Jul 21, 2011 7:37 am
yup, the solution makes sense, but you are right, one would be better picking numbers for this.

Thanks a ton !!
Cheers !!

Quant 47-Striving for 50
Verbal 34-Striving for 40

My gmat journey :
https://www.beatthegmat.com/710-bblast-s ... 90735.html
My take on the GMAT RC :
https://www.beatthegmat.com/ways-to-bbla ... 90808.html
How to prepare before your MBA:
https://www.youtube.com/watch?v=upz46D7 ... TWBZF14TKW_
Top
Post new topic Post Reply
• Page 1 of 1