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

It is currently 18 Dec 2014, 01:33

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

Is X>Y 1. X/3Y > 1/3 2. -X+P < -Y + P

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 17 Aug 2009
Posts: 238
Followers: 4

Kudos [?]: 100 [0], given: 25

Is X>Y 1. X/3Y > 1/3 2. -X+P < -Y + P [#permalink] New post 23 Nov 2009, 10:05
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

67% (01:58) correct 33% (00:36) wrong based on 13 sessions
Is X>Y

1. X/3Y > 1/3
2. -X+P < -Y + P
Senior Manager
Senior Manager
User avatar
Joined: 21 Jul 2009
Posts: 366
Schools: LBS, INSEAD, IMD, ISB - Anything with just 1 yr program.
Followers: 14

Kudos [?]: 103 [0], given: 22

Re: Is x>y ? [#permalink] New post 23 Nov 2009, 10:39
zaarathelab wrote:
Is X>Y

1. X/3Y > 1/3
2. -X+P < -Y + P


Stmt 1- X/Y > 3/3 implies that X/Y > 1. Multiplying Y on both sides, X > Y - Suff
Stmt 2- -X+P < -Y+P. Subtracting P on both sides -X < -Y. Multiplying with -1 on both sides, note, when you multiply with -1 on both sides the comparison side changes. So if -X < -Y then X > Y. - Suff.

Hence, D is the answer.
_________________

I am AWESOME and it's gonna be LEGENDARY!!!

Manager
Manager
avatar
Joined: 07 Jul 2009
Posts: 230
Followers: 3

Kudos [?]: 46 [0], given: 13

Re: Is x>y ? [#permalink] New post 23 Nov 2009, 10:59
It's B.

Stmt 1: X/3Y>1/3
Multiply both side by 3 and we get X/Y>1
We have two conditions here (X and Y can be both positive or both negative):
1) If both X and Y are positive then X > Y
2) If both X and Y are negative, then X < Y

So, stmt 1 is NOT sufficient

Stmt 2: -X+P < -Y + P
Subtract P from both sides and we get –X < -Y
Multiply both sides by -1 and we get X>Y

So stmt 2 is sufficient.

Answer is B
VP
VP
avatar
Joined: 05 Mar 2008
Posts: 1474
Followers: 11

Kudos [?]: 209 [0], given: 31

Re: Is x>y ? [#permalink] New post 23 Nov 2009, 11:00
zaarathelab wrote:
Is X>Y

1. X/3Y > 1/3
2. -X+P < -Y + P


Answer B

1. Insufficient: x and y < 0 or x and y > o
Intern
Intern
User avatar
Joined: 17 Nov 2009
Posts: 47
Followers: 1

Kudos [?]: 7 [0], given: 2

Re: Is x>y ? [#permalink] New post 23 Nov 2009, 12:08
SensibleGuy wrote:
zaarathelab wrote:
Is X>Y

1. X/3Y > 1/3
2. -X+P < -Y + P


Stmt 1- X/Y > 3/3 implies that X/Y > 1. Multiplying Y on both sides, X > Y - Suff
Stmt 2- -X+P < -Y+P. Subtracting P on both sides -X < -Y. Multiplying with -1 on both sides, note, when you multiply with -1 on both sides the comparison side changes. So if -X < -Y then X > Y. - Suff.

Hence, D is the answer.


It is B
YYou cannot go from X/Y > 1 to X > Y (Multiplying Y on both sides) without knowing the sign of Y.
2 KUDOS received
Intern
Intern
User avatar
Affiliations: University of Florida Alumni
Joined: 25 Oct 2009
Posts: 36
Schools: Wharton, Booth, Stanford, HBS
Followers: 0

Kudos [?]: 14 [2] , given: 11

Re: Is x>y ? [#permalink] New post 23 Nov 2009, 12:11
2
This post received
KUDOS
Cancelling out "common terms" on both sides of an equation

You need to be very careful when you do algebra derivations. One of the common mistake is to divide both side by "a common term". Remember you can only do this safely if the "common term" is a constant. However you CAN't do it if it contains a variable.

Example:

x(x-2)=x
You can't cancel out the x on both side and say x=3 is the solution. You must move the x on the right side to the left side.
x(x-2)-x=0
x(x-2-1)=0
The solutions are: x=0 and x=3
The reason why you can't divided both sides by x is that when x is zero, you can't divide anything by zero.

Equally important if not more, is that you CAN'T multiple or divide a "common term" that includes a variable from both side of an inequality. Not only it could be zero, but it could also be negative in which case you would need to flip the sign.

Example:

x^2>x
You CAN'T divided both sides by x and say x>1. What you have to do is to move the right side to the left:
x^2-x>0
x(x-1)>0
Solution would be either both x and x-1 are greater than zero, or both x and x-1 are smaller than zero. So your solution is: x>1 or x<0

Example:

x>1/x
Again you CAN'T multiply both sides by x because you don't know if x is positive or negative. What you have to do is to move the right side to the left:
x-1/x>0
(x^2-1)/x>0
If x>0 then x^2-1>0 =>x>1
If x<0 then x^2-1<0 =>x>-1
Therefore your solution is x>1 or 0>x>-1.
You could also break the original question to two branches from the beginning:
x>1/x
if x>0 then x^2>1 =>x>1
if x<0 then x^2<1 => x>-1
Therefore your solution is x>1 or 0>x>-1.
_________________

Kudos are greatly appreciated and I'll always return the favor on one of your posts.

Thanks!

Senior Manager
Senior Manager
User avatar
Joined: 21 Jul 2009
Posts: 366
Schools: LBS, INSEAD, IMD, ISB - Anything with just 1 yr program.
Followers: 14

Kudos [?]: 103 [0], given: 22

Re: Is x>y ? [#permalink] New post 23 Nov 2009, 13:17
arrrrggghhhhh!!! The nightmares of number theory will continue to haunt me!!!!
_________________

I am AWESOME and it's gonna be LEGENDARY!!!

Manager
Manager
avatar
Joined: 22 Jul 2009
Posts: 205
Location: Manchester UK
Followers: 2

Kudos [?]: 60 [0], given: 6

Re: Is x>y ? [#permalink] New post 17 Dec 2009, 02:04
This was awesome.....
Re: Is x>y ?   [#permalink] 17 Dec 2009, 02:04
    Similar topics Author Replies Last post
Similar
Topics:
24 Experts publish their posts in the topic If xy 0, is x > y? (1) 4x = 3y (2) |y - x| = x - y Economist 20 12 Nov 2009, 08:45
(D/S) |2X| = |3Y|, is X >Y? pretttyune 5 10 Dec 2007, 05:08
2 If x = 3y, is x^2 > y^2? iced_tea 7 08 Oct 2006, 22:14
If x = 3y, is x^2 > y^2? 1. y+x < x-y 2. x^2 = 9 y^2 haas_mba07 4 14 Sep 2006, 05:41
If x=3y, is x^2>y^2? 1). y+x<y*x 2). X^2=9y^2 OA is A getzgetzu 3 23 Nov 2005, 22:35
Display posts from previous: Sort by

Is X>Y 1. X/3Y > 1/3 2. -X+P < -Y + P

  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®.