Find all School-related info fast with the new School-Specific MBA Forum

It is currently 25 May 2015, 08:14

Today:

Free Access to GMAT Club Tests - May 25th for Memorial Day!!


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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If y does not equal 0. Does x = 0 ?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Director
Director
User avatar
Joined: 07 Jun 2004
Posts: 614
Location: PA
Followers: 3

Kudos [?]: 290 [1] , given: 22

If y does not equal 0. Does x = 0 ? [#permalink] New post 06 Jan 2011, 05:32
1
This post received
KUDOS
4
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

52% (02:22) correct 48% (00:56) wrong based on 172 sessions
If y does not equal 0. Does x = 0 ?

(1) x^2*y = x^3*y
(2) x^2/y = x^3*y
[Reveal] Spoiler: OA

Last edited by Bunuel on 07 Oct 2014, 06:55, edited 2 times in total.
OA added.
Expert Post
2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 27492
Followers: 4312

Kudos [?]: 42276 [2] , given: 6012

Re: If y does not equal 0. Does x = 0 ? [#permalink] New post 06 Jan 2011, 05:45
2
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
rxs0005 wrote:
If y <> = 0 Does x = 0

x^2 y = x^3 y

x^2 / y = x^3 y


Given: \(y\neq{0}\). Question does \(x=0\)?

(1) x^2*y=x^3*y --> as \(y\neq{0}\) we can reduce by \(y\) --> \(x^2=x^3\) --> \(x^2(x-1)=0\) --> either \(x=0\) or \(x=1\). Not sufficient.

(2) x^2/y=x^3*y --> \(x^2=x^3y^2\) --> \(x^2(xy^2-1)=0\) --> either \(x=0\) or \(xy^2=1\) (depending on \(y\) \(x\) can be any positive number). Not sufficient.

(1)+(2) Both \(x=0\) and \(x=1\) (in this case \(y=1\) or \(y=-1\)) satisfy the statements. Not sufficient.

Answer: E.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
User avatar
Joined: 20 Jul 2011
Posts: 152
GMAT Date: 10-21-2011
Followers: 1

Kudos [?]: 43 [0], given: 15

Re: If y does not equal 0. Does x = 0 ? [#permalink] New post 07 Sep 2011, 04:19
**
Quote:
If y <> = 0 Does x = 0

(1) x^2 y = x^3 y

(2) x^2 / y = x^3 y


Very clear explanation, Bunuel. Thanks!
Initially, I had answer A and realised my mistake after reading Bunuel's solution. My error came from the fact that I cross-multiplied and eliminated as below:
Quote:
From Statement 1
--> x^2y=x^3y --> y/y = x^3/x^2 --> x = 1
Sufficient


Given y does not equal to zero, does x=0?

Statement 1
x^2y = x^3y --> x^3=x^2 --> 0 = x^2(x-1)
So, x=0 or x=1
Insufficient.

Statement 2
x^2/y = x^3y --> 0 = x^2(xy^2-1)
So, x=0 or xy^2=1 (i.e. x is not zero)
Insufficient.

Statement 1 + 2
x^2(x-1) = x^2(xy^2-1)
x-1 = xy^2-1
x(1-y^2) = 0
So, x = 0 or x does not equals to zero (when y^2=1)
Insufficient.

Answer: E
_________________

"The best day of your life is the one on which you decide your life is your own. No apologies or excuses. No one to lean on, rely on, or blame. The gift is yours - it is an amazing journey - and you alone are responsible for the quality of it. This is the day your life really begins." - Bob Moawab

Director
Director
User avatar
Status: Final Countdown
Joined: 17 Mar 2010
Posts: 564
Location: India
GPA: 3.82
WE: Account Management (Retail Banking)
Followers: 13

Kudos [?]: 169 [0], given: 75

Re: If y does not equal 0. Does x = 0 ? [#permalink] New post 26 Aug 2012, 09:55
Very nice explanation Bunuel , thanks a lot !

I was confused whether to choose D or E because i thought that in either of the options x is coming 0 (along with some other value)

But it suggests that the value is not sufficient in both the cases.
_________________

" Make more efforts "
Press Kudos if you liked my post

Senior Manager
Senior Manager
avatar
Joined: 02 Sep 2012
Posts: 293
Location: United States
Concentration: Entrepreneurship, Finance
GMAT Date: 07-25-2013
GPA: 3.83
WE: Architecture (Computer Hardware)
Followers: 3

Kudos [?]: 96 [0], given: 99

Re: If y does not equal 0. Does x = 0 ? [#permalink] New post 29 Dec 2012, 01:21
If y does not equal 0. Does x = 0 ?

(1) x^2 y = x^3 y
(2) x^2 / y = x^3 y

please do calrify my doubt :

Given:
y does not equal to zero, does x=0?

x^2y = x^3y

Here we are calculating as x^2y-x^3y
my question is
why can't we do as x^2y/x^3y

Please do clarify when what is the actual procedure and why can't do like this as mentioned later
_________________

"Giving kudos" is a decent way to say "Thanks" and motivate contributors. Please use them, it won't cost you anything

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 27492
Followers: 4312

Kudos [?]: 42276 [0], given: 6012

Re: If y does not equal 0. Does x = 0 ? [#permalink] New post 29 Dec 2012, 02:51
Expert's post
skamal7 wrote:
If y does not equal 0. Does x = 0 ?

(1) x^2 y = x^3 y
(2) x^2 / y = x^3 y

please do calrify my doubt :

Given:
y does not equal to zero, does x=0?

x^2y = x^3y

Here we are calculating as x^2y-x^3y
my question is
why can't we do as x^2y/x^3y

Please do clarify when what is the actual procedure and why can't do like this as mentioned later


Merging similar topics. Please refer to the solutions above.

Also, please read carefully and follow: rules-for-posting-please-read-this-before-posting-133935.html Pay attention to the rule #3.

Next, I guess your question is why are not we dividing both parts of x^2*y = x^3*y by x^3*y to get x^2*y/(x^3*y) = 1. That's because x^3*y can be zero (in case y=0) and we cannot divide by 0.

Hope it's clear.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 4933
Followers: 297

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

Premium Member
Re: If y does not equal 0. Does x = 0 ? [#permalink] New post 13 Nov 2014, 13:43
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

Re: If y does not equal 0. Does x = 0 ?   [#permalink] 13 Nov 2014, 13:43
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic Does x + y = 0? Bunuel 4 11 Dec 2014, 06:05
6 Experts publish their posts in the topic If x and y are integers and xy does not equal 0, is xy < 0? Bunuel 3 15 Oct 2014, 15:49
If x and y are integers and xy does not equal 0, is xy < 0? manalq8 0 27 Aug 2014, 06:20
4 Experts publish their posts in the topic If x does not equal y, and xy does not equal 0, then when x Phaser 9 02 Nov 2010, 00:48
4 Experts publish their posts in the topic If |x| - |y| = |x+y| and xy does not equal to 0, which of WholeLottaLove 16 30 May 2013, 15:40
Display posts from previous: Sort by

If y does not equal 0. Does x = 0 ?

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.