It is currently 16 Dec 2017, 07:15

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 ?

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

Hide Tags

1 KUDOS received
Retired Moderator
User avatar
B
Joined: 10 May 2010
Posts: 823

Kudos [?]: 442 [1], given: 192

GMAT ToolKit User Premium Member
Is x > y ? [#permalink]

Show Tags

New post 14 May 2012, 10:34
1
This post received
KUDOS
11
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

62% (00:51) correct 38% (00:51) wrong based on 349 sessions

HideShow timer Statistics

Is x > y ?

(1) x = 4y^2
(2) x > 1
[Reveal] Spoiler: OA

_________________

The question is not can you rise up to iconic! The real question is will you ?

Kudos [?]: 442 [1], given: 192

Expert Post
7 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42628

Kudos [?]: 135818 [7], given: 12715

Re: Is x > y ? (1) x = 4y^2 (2) x > 1 [#permalink]

Show Tags

New post 16 May 2012, 00:57
7
This post received
KUDOS
Expert's post
3
This post was
BOOKMARKED
Is x > y ?

(1) x = 4y^2. If x=y=0 then the answer is NO but if x=4 and y=1 then the answer is YES. Not sufficient.

(2) x > 1. Not sufficient.

(1)+(2) \(x = 4y^2\) --> \(y=\frac{\sqrt{x}}{2}\) (or \(y=-\frac{\sqrt{x}}{2}=negative\)). Now, since \(x>1\) then \(x>\sqrt{x}\), so \(x>(\frac{\sqrt{x}}{2}=y)\). Sufficient.

Answer: C.
_________________

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 [?]: 135818 [7], given: 12715

Retired Moderator
User avatar
B
Joined: 10 May 2010
Posts: 823

Kudos [?]: 442 [0], given: 192

GMAT ToolKit User Premium Member
Re: Is x > y ? (1) x = 4y^2 (2) x > 1 [#permalink]

Show Tags

New post 16 May 2012, 02:26
Thanks Bunuel, could you point to other similar inequalities problems.
_________________

The question is not can you rise up to iconic! The real question is will you ?

Kudos [?]: 442 [0], given: 192

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42628

Kudos [?]: 135818 [1], given: 12715

Re: Is x > y ? (1) x = 4y^2 (2) x > 1 [#permalink]

Show Tags

New post 16 May 2012, 02:30
1
This post received
KUDOS
Expert's post

Kudos [?]: 135818 [1], given: 12715

Intern
Intern
avatar
Joined: 21 Mar 2013
Posts: 13

Kudos [?]: 3 [0], given: 13

Re: Is x > y ? (1) x = 4y^2 (2) x > 1 [#permalink]

Show Tags

New post 06 Mar 2014, 15:22
Hi Bunuel,

i got 2 approaches yielding different results. Can you please take a look?

1. Approach

x = 4y^2 ; 1 < x

=> 1 < 4y^2 => 1/4 < y^2

2. Approach

x = 4y^2 ; 1 < x

=> x/x = (4y^2)/x
1 = (4y^2)/x

but if 1 < x then (4y^2)/x < x => 4y^2 < 1 => y^2 < 1/4


Where is the flaw ?

Thanks in advance

Bunuel wrote:
Is x > y ?

(1) x = 4y^2. If x=y=0 then the answer is NO but if x=4 and y=1 then the answer is YES. Not sufficient.

(2) x > 1. Not sufficient.

(1)+(2) \(x = 4y^2\) --> \(y=\frac{\sqrt{x}}{2}\) (or \(y=-\frac{\sqrt{x}}{2}=negative\)). Now, since \(x>1\) then \(x>\sqrt{x}\), so \(x>(\frac{\sqrt{x}}{2}=y)\). Sufficient.

Answer: C.

Kudos [?]: 3 [0], given: 13

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42628

Kudos [?]: 135818 [1], given: 12715

Re: Is x > y ? (1) x = 4y^2 (2) x > 1 [#permalink]

Show Tags

New post 07 Mar 2014, 00:50
1
This post received
KUDOS
Expert's post
mariofelix wrote:
Hi Bunuel,

i got 2 approaches yielding different results. Can you please take a look?

1. Approach

x = 4y^2 ; 1 < x

=> 1 < 4y^2 => 1/4 < y^2

2. Approach

x = 4y^2 ; 1 < x

=> x/x = (4y^2)/x
1 = (4y^2)/x

but if 1 < x then (4y^2)/x < x => 4y^2 < 1 => y^2 < 1/4


Where is the flaw ?

Thanks in advance

Bunuel wrote:
Is x > y ?

(1) x = 4y^2. If x=y=0 then the answer is NO but if x=4 and y=1 then the answer is YES. Not sufficient.

(2) x > 1. Not sufficient.

(1)+(2) \(x = 4y^2\) --> \(y=\frac{\sqrt{x}}{2}\) (or \(y=-\frac{\sqrt{x}}{2}=negative\)). Now, since \(x>1\) then \(x>\sqrt{x}\), so \(x>(\frac{\sqrt{x}}{2}=y)\). Sufficient.

Answer: C.


\(\frac{(4y^2)}{x} < x\) --> \(4y^2 < x^2\), not \(4y^2 < 1\).
_________________

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 [?]: 135818 [1], given: 12715

Intern
Intern
avatar
Joined: 03 Jul 2013
Posts: 45

Kudos [?]: 7 [0], given: 9

Concentration: Entrepreneurship, International Business
Re: Is x > y ? [#permalink]

Show Tags

New post 08 Mar 2014, 04:36
easy to eliminate ADB

answer is C

Stat 1: x = 4y^2
Stat 2: x>1

1+2: since x > 1( x^2 is always greater that x) and y^2 is also positive. It follows that lxl = 4ly^2l
hence, x> y

Kudos [?]: 7 [0], given: 9

Manager
Manager
avatar
B
Joined: 23 May 2013
Posts: 189

Kudos [?]: 120 [0], given: 42

Location: United States
Concentration: Technology, Healthcare
Schools: Stanford '19 (M)
GMAT 1: 760 Q49 V45
GPA: 3.5
GMAT ToolKit User
Re: Is x > y ? [#permalink]

Show Tags

New post 20 Aug 2015, 10:04
To solve these types of inequality questions, it's useful to see the ranges where x>y, x<y, and where x=y.

1) To start off, we know that \(x = 4y^2\). If we wanna see where x=y, set both variables equal to each other.

x = 4x^2
1 = 4x (dividing by y means we have to consider the case when x = 0. Notice in this case that x = y.
x = 1/4.

So our critical values here are y = 0 and x = 1/4.

<-------(0)--------(1/4)-------->

If x<0 (for instance, -1, then y = 4), x<y
if 0<x<1/4 (for instance, 1/8, then y =1/16) x>y
If x>1/4 (for instance, x = 1, y= 4) x<y

So, for x to be greater than y, x has be greater than 0 and less than 1/4. This is not enough information on its own. Insufficient.

2) is obviously not enough information on its own. Insufficient.

However, if we know that x>1, we know that it's outside this range and therefore that x<y.

We need both pieces of information. Therefore answer: C

Kudos [?]: 120 [0], given: 42

Retired Moderator
avatar
Joined: 29 Oct 2013
Posts: 285

Kudos [?]: 506 [0], given: 197

Concentration: Finance
GPA: 3.7
WE: Corporate Finance (Retail Banking)
GMAT ToolKit User
Is x > y ? [#permalink]

Show Tags

New post 17 Feb 2016, 12:08
Ans C

Please check the solution in the picture attached
Attachments

Capture.PNG
Capture.PNG [ 932.48 KiB | Viewed 3885 times ]


_________________

Please contact me for super inexpensive quality private tutoring

My journey V46 and 750 -> http://gmatclub.com/forum/my-journey-to-46-on-verbal-750overall-171722.html#p1367876

Kudos [?]: 506 [0], given: 197

Retired Moderator
User avatar
P
Joined: 12 Aug 2015
Posts: 2218

Kudos [?]: 910 [0], given: 610

GRE 1: 323 Q169 V154
GMAT ToolKit User Premium Member
Re: Is x > y ? [#permalink]

Show Tags

New post 13 Mar 2016, 08:02
For any inequality we must the check the bound (-1,0) and (0,1)
THEY BEHAVE FUNNY WHEN SQUARED....
WRITE THAT DOWN...
_________________

Give me a hell yeah ...!!!!!

Kudos [?]: 910 [0], given: 610

Top Contributor
Director
Director
User avatar
B
Status: I don't stop when I'm Tired,I stop when I'm done
Joined: 11 May 2014
Posts: 563

Kudos [?]: 3066 [0], given: 220

Location: Bangladesh
Concentration: Finance, Leadership
GPA: 2.81
WE: Business Development (Real Estate)
Re: Is x > y ? [#permalink]

Show Tags

New post 10 Aug 2016, 05:37
Top Contributor
AbhiJ wrote:
Is x > y ?

(1) x = 4y^2
(2) x > 1


(1)
    when y=\(\frac{1}{2}\),then x=4\((\frac{1}{2})^2\)=1,so x>Y
    When y=\(\frac{1}{4}\),then x=4\((\frac{1}{4})^2\)=\(\frac{1}{4}\),x=y,Not Sufficient

(2) No information about y ,Clearly Not sufficient

(1)+(2) when x>1 ,x is always greater than y in terms of the equation from Statement (1),Sufficient

Correct Answer C
_________________

Md. Abdur Rakib

Please Press +1 Kudos,If it helps
Sentence Correction-Collection of Ron Purewal's "elliptical construction/analogies" for SC Challenges

Kudos [?]: 3066 [0], given: 220

Intern
Intern
avatar
Joined: 31 May 2016
Posts: 4

Kudos [?]: [0], given: 6

Re: Is x > y ? [#permalink]

Show Tags

New post 11 Aug 2016, 04:38
Is x > y ?

(1) x = 4y^2 ---> It represents the equation of parabola symmetric towards Ist and 4th quadrant , x can be +ve or zero
if any +ve value , y> x , for x=0 , x=y=0; ( INSUFF)

(2) x > 1 --- standalone not sufficient

by combining we know that x is value greater than > 1 , and it is always smaller than y

(C) is the answer

Kudos [?]: [0], given: 6

Senior Manager
Senior Manager
avatar
S
Joined: 07 Sep 2014
Posts: 482

Kudos [?]: 40 [0], given: 342

Concentration: Finance, Marketing
Re: Is x > y ? [#permalink]

Show Tags

New post 23 Aug 2016, 03:22
Is x > y ?

(1) x = 4y^2
(2) x > 1

(1) x = 4y^2

if y =0 => x =0 No
if y =1 & x= 4 yes
if y= 1/2 x = 1 yes

(2) x > 1

both combined yes

Kudos [?]: 40 [0], given: 342

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 14813

Kudos [?]: 288 [0], given: 0

Premium Member
Re: Is x > y ? [#permalink]

Show Tags

New post 02 Sep 2017, 01:48
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Kudos [?]: 288 [0], given: 0

Re: Is x > y ?   [#permalink] 02 Sep 2017, 01:48
Display posts from previous: Sort by

Is x > y ?

  new topic 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®.