GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 18 Dec 2018, 23:36

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 in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • Happy Christmas 20% Sale! Math Revolution All-In-One Products!

     December 20, 2018

     December 20, 2018

     10:00 PM PST

     11:00 PM PST

    This is the most inexpensive and attractive price in the market. Get the course now!
  • Key Strategies to Master GMAT SC

     December 22, 2018

     December 22, 2018

     07:00 AM PST

     09:00 AM PST

    Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.

If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0

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

Hide Tags

Director
Director
User avatar
Joined: 07 Jun 2004
Posts: 599
Location: PA
If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0  [#permalink]

Show Tags

New post 04 Dec 2010, 02:10
1
3
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

54% (01:51) correct 46% (01:52) wrong based on 297 sessions

HideShow timer Statistics

If xy > 0, does xy – y = 3?

(1) xy = 3
(2) y – 1 = 0

_________________

If the Q jogged your mind do Kudos me : )

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51291
Re: Algebra DS  [#permalink]

Show Tags

New post 04 Dec 2010, 02:22
3
1
rxs0005 wrote:
If xy > 0, does xy – y = 3?

(1) xy = 3
(2) y – 1 = 0


If xy > 0, does xy – y = 3?

(1) xy = 3 --> question becomes: is \(3-y=3\)? or is \(y=0\)? Since given that \(xy>0\) (or the same \(xy=3\)) then it's clear that \(y\neq{0}\) so we have the answer NO. Sufficient.

(2) y – 1 = 0 --> question becomes: is \(x=4\)? We don't know that. Not sufficient.

Answer: A.
_________________

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

Director
Director
User avatar
Joined: 07 Jun 2004
Posts: 599
Location: PA
Re: Algebra DS  [#permalink]

Show Tags

New post 04 Dec 2010, 03:21
1
thanks great explanation
_________________

If the Q jogged your mind do Kudos me : )

Manager
Manager
avatar
Joined: 02 Oct 2010
Posts: 99
Re: Algebra DS  [#permalink]

Show Tags

New post 19 Dec 2010, 21:22
Bunuel wrote:
rxs0005 wrote:
If xy > 0, does xy – y = 3?

(1) xy = 3
(2) y – 1 = 0


If xy > 0, does xy – y = 3?

(1) xy = 3 --> question becomes: is \(3-y=3\)? or is \(y=0\)? Since given that \(xy>0\) (or the same \(xy=3\)) then it's clear that \(y\neq{0}\) so we have the answer NO. Sufficient.
(2) y – 1 = 0 --> question becomes: is \(x=4\)? We don't know that. Not sufficient.

Answer: A.



Good Explanation....
Senior Manager
Senior Manager
avatar
Status: Up again.
Joined: 31 Oct 2010
Posts: 492
Concentration: Strategy, Operations
GMAT 1: 710 Q48 V40
GMAT 2: 740 Q49 V42
Re: Algebra DS  [#permalink]

Show Tags

New post 24 Jan 2011, 00:47
Bunuel wrote:
rxs0005 wrote:
If xy > 0, does xy – y = 3?

(1) xy = 3
(2) y – 1 = 0


If xy > 0, does xy – y = 3?

(1) xy = 3 --> question becomes: is \(3-y=3\)? or is \(y=0\)? Since given that \(xy>0\) (or the same \(xy=3\)) then it's clear that \(y\neq{0}\) so we have the answer NO. Sufficient.
(2) y – 1 = 0 --> question becomes: is \(x=4\)? We don't know that. Not sufficient.

Answer: A.


Great! With your explanations, I am getting better at seeing through the equations and manipulating them! Thanks Kudos!
_________________

My GMAT debrief: http://gmatclub.com/forum/from-620-to-710-my-gmat-journey-114437.html

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51291
Re: If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0  [#permalink]

Show Tags

New post 03 Jul 2013, 00:17
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

Theory on Algebra: algebra-101576.html

DS Algebra Questions to practice: search.php?search_id=tag&tag_id=29
PS Algebra Questions to practice: search.php?search_id=tag&tag_id=50

Special algebra set: new-algebra-set-149349.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

Intern
Intern
avatar
Joined: 05 May 2013
Posts: 23
GMAT 1: 730 Q50 V39
GRE 1: Q800 V680
Re: If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0  [#permalink]

Show Tags

New post 03 Jul 2013, 03:01
1
From (1), xy-y = 3-y ; this is equal to 3 only if y=0 , but since its given that xy =3 neither x nor y can be 0. Therefore, given (1) xy-y is not equal to 3. Sufficient.
(2) simplifies the question to is x-1=3 or is x=4 which cannot be answered with this information. Insufficient.
Director
Director
User avatar
Joined: 25 Apr 2012
Posts: 683
Location: India
GPA: 3.21
WE: Business Development (Other)
Premium Member Reviews Badge
Re: If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0  [#permalink]

Show Tags

New post 03 Jul 2013, 08:29
1
rxs0005 wrote:
If xy > 0, does xy – y = 3?

(1) xy = 3
(2) y – 1 = 0



From the given statement xy>0, we can deduce that either x,y>0 or x,y< 0

St1 we have xy=3
possible values of x and y are

x=-1, y=-3, substituting in the given we get 3-(-3)=6 which is not equal to 3
x=3,y=1, we get 3-1= 2 not equal 3
x=9,y=1/3 3- 1/3= 8/3 not equal to 3

we can safely that say that for any values satisfying given st1 we do not have the expression value equal 3

Hence Option B,C,E ruled out

St 2, y-1=0-----> y=1
we know only the value of y and that x>0 which is not sufficient. In order to satisfy the given equation that is xy-y=3 value of x should be 4 which we are not sure of.

Hence Ans should be A :)

thanks
_________________


“If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.”

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9199
Premium Member
Re: If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0  [#permalink]

Show Tags

New post 17 Aug 2018, 16:52
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

GMAT Club Bot
Re: If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0 &nbs [#permalink] 17 Aug 2018, 16:52
Display posts from previous: Sort by

If xy > 0, does xy y = 3? (1) xy = 3 (2) y 1 = 0

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.