It is currently 23 Sep 2017, 09:56

Happening Now:

Alleviate MBA app anxiety! Come to Chat Room #2


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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Dear People, Just ran into some fresh difficulties during my

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 01 May 2009
Posts: 41

Kudos [?]: 38 [0], given: 0

Dear People, Just ran into some fresh difficulties during my [#permalink]

Show Tags

New post 18 Jul 2009, 21:09
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Dear People,

Just ran into some fresh difficulties during my revision on DS...

The question is as below:

Is x^2 equal to xy?
(1) x^2 – y^2 = (x + 5)(y - 5)
(2) x = y


I feel that Statement 1 is quite deceiving, since only one part of it answers the question, while the other part seems irrelevant.

Please provide some explanations & workings if possible. THank you very much.

Kudos [?]: 38 [0], given: 0

SVP
SVP
User avatar
B
Joined: 05 Jul 2006
Posts: 1742

Kudos [?]: 418 [0], given: 49

GMAT ToolKit User
Re: What Happens if Only Half the Statement is Sufficient? [#permalink]

Show Tags

New post 19 Jul 2009, 10:30
[quote="cialit0506"]Dear People,

Just ran into some fresh difficulties during my revision on DS...

The question is as below:

Is x^2 equal to xy?
(1) x^2 – y^2 = (x + 5)(y - 5)
(2) x = y


x^2 can = xy only if /x/=/y/ or x = 0

(x-y)(x+y) = (x+5)(y-5)

if we assume that (x-y) = (x+5) thus y = -5 and if we assumed that(x+y) = (y-5) = then x=-5 either ways /y/=/x/
x = +or-ve 5 and so is y ie // is the same .............suff

from b.....obvious suff

answer is D

Last edited by yezz on 19 Jul 2009, 14:51, edited 1 time in total.

Kudos [?]: 418 [0], given: 49

Senior Manager
Senior Manager
avatar
Joined: 04 Jun 2008
Posts: 289

Kudos [?]: 150 [0], given: 15

Re: What Happens if Only Half the Statement is Sufficient? [#permalink]

Show Tags

New post 19 Jul 2009, 12:19
I am unable to see how stmt 1 is sufficient. Can someone please explain?

Kudos [?]: 150 [0], given: 15

Intern
Intern
avatar
Joined: 01 May 2009
Posts: 41

Kudos [?]: 38 [0], given: 0

Re: What Happens if Only Half the Statement is Sufficient? [#permalink]

Show Tags

New post 23 Jul 2009, 08:21
Yeap, got it. Thanks a million :)

Kudos [?]: 38 [0], given: 0

Manager
Manager
avatar
Joined: 15 Apr 2008
Posts: 50

Kudos [?]: 23 [0], given: 8

Location: Moscow
Re: What Happens if Only Half the Statement is Sufficient? [#permalink]

Show Tags

New post 24 Jul 2009, 03:01
yezz wrote:
(x-y)(x+y) = (x+5)(y-5)

if we assume that (x-y) = (x+5) thus y = -5 and if we assumed that(x+y) = (y-5) = then x=-5 either ways /y/=/x/
x = +or-ve 5 and so is y ie // is the same .............suff

If a*b=c*d, it's not right to assume that a is equal either to c or d. a is a factor or a multiple of either c or d.
In this problem if x=5, than \(25-y^2=10*y-50\)
\(y^2+10*y-75=0\)
which gives us 2 solutions: y1=5 and y2=-15
And as we are not given that x and y are integers, we can plug in any value of x and solve for y.
Hence, insuff. Nevertheless, working out a solution when x=y is necessary to prove that statement 1 is insuff. If there were no solution when x=y at all, then Stat.1 would be sufficient and the answer would be "no".

Kudos [?]: 23 [0], given: 8

Re: What Happens if Only Half the Statement is Sufficient?   [#permalink] 24 Jul 2009, 03:01
Display posts from previous: Sort by

Dear People, Just ran into some fresh difficulties during my

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.