It is currently 24 Sep 2017, 01:35

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

Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

1 KUDOS received
Manager
Manager
avatar
Joined: 14 Jun 2008
Posts: 162

Kudos [?]: 36 [1], given: 0

Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0 [#permalink]

Show Tags

New post 02 Sep 2008, 07:41
1
This post received
KUDOS
4
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

35% (02:06) correct 65% (01:34) wrong based on 171 sessions

HideShow timer Statistics

Is x > y^2?

(1) x > y + 5
(2) x^2 - y^2 = 0

OPEN DISCUSSION OF THIS QUESTION IS HERE: is-x-y-2-1-x-y-5-2-x-2-y-97142.html
[Reveal] Spoiler: OA

Last edited by Bunuel on 22 Jun 2012, 07:35, edited 1 time in total.
Edited the question and added the OA. Topic is locked.

Kudos [?]: 36 [1], given: 0

Manager
Manager
avatar
Joined: 22 Jul 2008
Posts: 149

Kudos [?]: 18 [0], given: 0

Re: DS : m02 #19 [#permalink]

Show Tags

New post 02 Sep 2008, 08:08
St 2 : x^2 = y^2 Hence x cannot be > y^2.
St.1: x> y+5. Multiple values can be substituted for x, y.-- Insufficient
Therefore, ans should be B

Kudos [?]: 18 [0], given: 0

SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1795

Kudos [?]: 1035 [0], given: 5

Location: New York
Re: DS : m02 #19 [#permalink]

Show Tags

New post 02 Sep 2008, 08:23
KASSALMD wrote:
St 2 : x^2 = y^2 Hence x cannot be > y^2.
St.1: x> y+5. Multiple values can be substituted for x, y.-- Insufficient
Therefore, ans should be B


x=1/2 y=1/2 x>y^2 true

x=2 y=2 x>y^2 false
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning

Kudos [?]: 1035 [0], given: 5

SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1795

Kudos [?]: 1035 [0], given: 5

Location: New York
Re: DS : m02 #19 [#permalink]

Show Tags

New post 02 Sep 2008, 11:49
Guys,

Its not B.

For Statement 2:
There are two answers.. Insufficient.
x=1/2 y=1/2 x>y^2 true

x=2 y=2 x>y^2 false

combine

x and y must have opposite sign because x>y+5

x>-x+5
x>2.5

Sufficient

Should be C.
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning

Kudos [?]: 1035 [0], given: 5

1 KUDOS received
Intern
Intern
avatar
Joined: 19 Sep 2006
Posts: 19

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

Re: DS : m02 #19 [#permalink]

Show Tags

New post 02 Sep 2008, 12:04
1
This post received
KUDOS
Real good one! Thanks for the post.

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

2 KUDOS received
Manager
Manager
avatar
Joined: 14 Jun 2008
Posts: 162

Kudos [?]: 36 [2], given: 0

Re: DS : m02 #19 [#permalink]

Show Tags

New post 02 Sep 2008, 14:21
2
This post received
KUDOS
x2suresh wrote:
Guys,

Its not B.

For Statement 2:
There are two answers.. Insufficient.
x=1/2 y=1/2 x>y^2 true

x=2 y=2 x>y^2 false

combine

x and y must have opposite sign because x>y+5

x>-x+5
x>2.5


Sufficient

Should be C.


thats the trick.
good stuff

OA is C

Kudos [?]: 36 [2], given: 0

1 KUDOS received
Intern
Intern
avatar
Status: Single
Joined: 16 Dec 2011
Posts: 17

Kudos [?]: 15 [1], given: 6

GMAT 1: 600 Q42 V31
GPA: 3.5
GMAT ToolKit User
Re: Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0 struggling [#permalink]

Show Tags

New post 22 Jun 2012, 05:45
1
This post received
KUDOS
Thnx For the explanation

Kudos [?]: 15 [1], given: 6

Manager
Manager
User avatar
Status: Juggg..Jugggg Go!
Joined: 11 May 2012
Posts: 243

Kudos [?]: 54 [0], given: 239

Location: India
GC Meter: A.W.E.S.O.M.E
Concentration: Entrepreneurship, General Management
GMAT 1: 620 Q46 V30
GMAT 2: 720 Q50 V38
Reviews Badge
Re: Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0 struggling [#permalink]

Show Tags

New post 22 Jun 2012, 07:30
seems like answer is C, as it is not mentioned they are integers!
_________________

You haven't failed, if you haven't given up!
---
bschooladmit
Visit my Blog www.bschooladmit.wordpress.com

Check out my other posts:
Bschool Deadlines 2013-2014 | Bschool Admission Events 2013 Start your GMAT Prep with Stacey Koprince | Get a head start in MBA finance

Kudos [?]: 54 [0], given: 239

Expert Post
2 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41699

Kudos [?]: 124701 [2], given: 12079

Re: Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0 [#permalink]

Show Tags

New post 22 Jun 2012, 07:35
2
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
Is \(x>y^2\)?

(1) \(x>y+5\) --> \(x-y>5\). Clearly insufficient, for example: if \(x=1\) and \(y=-10\) then the answer is NO, but if \(x=10\) and \(y=1\) then the answer is YES. Two different answers, hence not sufficient.

(2) \(x^2-y^2=0\) --> \((x-y)(x+y)=0\) --> so either \(x-y=0\) or \(x+y=0\). Also insufficient: if \(x=1\) and \(y=1\), then answer is NO, buy if \(x=\frac{1}{2}\) and \(y=\frac{1}{2}\), then the answer is YES. Two different answers, hence not sufficient.

(1)+(2) As from (1) \(x-y>5\neq{0}\), then from (2) must be true that \(x+y=0\) --> so \(x=-y\) --> substitute \(x\) in (1) --> \(-y-y>5\) --> \(y<-\frac{5}{2}<0\), as \(x=-y\), then \(x>\frac{5}{2}>0\), so \(y^2\) (or which is the same \(x^2\)) will always be more than \(x\), thus the answer to the question "Is \(x>y^2\)" is NO. Sufficient.

To elaborate more as \(x=-y>0\), the only chance for \(x>y^2\) to hold true (or which is the same for \(x>x^2\) to hold true) would be if \(x\) is fraction (\(0<x<1\)). For example if \(x=\frac{1}{2}\) and \(y=-\frac{1}{2}\) then \(x=\frac{1}{2}>y^2=\frac{1}{4}\). But the fact that \(x>\frac{5}{2}>0\) rules out this option.

Answer: C.

Hope it's clear.

OPEN DISCUSSION OF THIS QUESTION IS HERE: is-x-y-2-1-x-y-5-2-x-2-y-97142.html
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 124701 [2], given: 12079

Re: Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0   [#permalink] 22 Jun 2012, 07:35
Display posts from previous: Sort by

Is x > y^2? 1. x > y + 5 2. x^2 - y^2 = 0

  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®.