NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 02:53 It is currently 26 Apr 2024, 02:53
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

GMATPrep DS! Number Properties

SORT BY:
Date
Kudos
User avatar
jimmyjamesdonkey
Senior Manager
Senior Manager
Joined: 01 May 2007
Posts: 484
Own Kudos [?]: 1454 [0]
Given Kudos: 0
Send PM
GMATPrep DS! Number Properties [#permalink] New post   29 Dec 2007, 13:45
Is |x| > |y|?

1) x^2 > y^2

2) x > y
avatar
Mia.Andersson
Intern
Intern
Joined: 13 Nov 2007
Posts: 6
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
[#permalink] New post   29 Dec 2007, 19:13
A

1. Sufficient.
For all 4 positive and negative combinations of X and Y.

2. Not Sufficient.
e.g. X=-1 and Y=-2
avatar
Mia.Andersson
Intern
Intern
Joined: 13 Nov 2007
Posts: 6
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
[#permalink] New post   29 Dec 2007, 19:15
By the way, you posted the question in the wrong section i guess.
User avatar
Manbehindthecurtain
Manager
Manager
Joined: 06 Jan 2008
Posts: 204
Own Kudos [?]: 481 [0]
Given Kudos: 1
Send PM
Re: [#permalink] New post   10 Jan 2008, 18:58
How A?

What are the four positive and negative combinations? if x^2 and y^2 = x,-x and y,-y; I was thinking 1) says..
x>y : Yes to |x|>|y|
x>-y : Yes/No : (x = 100, -y = -2)/(x = 1, -y = -2)
-x>-y, ie: -1>-2, but |-1| is not > |-2|...

What am I missing about the combinations?


Mia.Andersson wrote:
A

1. Sufficient.
For all 4 positive and negative combinations of X and Y.

2. Not Sufficient.
e.g. X=-1 and Y=-2
User avatar
GMATBLACKBELT
VP
VP
Joined: 29 Mar 2007
Posts: 1150
Own Kudos [?]: 1737 [0]
Given Kudos: 0
Send PM
Re: Re: [#permalink] New post   10 Jan 2008, 19:45
Manbehindthecurtain wrote:
How A?

What are the four positive and negative combinations? if x^2 and y^2 = x,-x and y,-y; I was thinking 1) says..
x>y : Yes to |x|>|y|
x>-y : Yes/No : (x = 100, -y = -2)/(x = 1, -y = -2)
-x>-y, ie: -1>-2, but |-1| is not > |-2|...

What am I missing about the combinations?


Mia.Andersson wrote:
A

1. Sufficient.
For all 4 positive and negative combinations of X and Y.

2. Not Sufficient.
e.g. X=-1 and Y=-2


|x| is essentially x^2 in terms of sign that is.

Essentially anything to the ^2 power is going to be positive or 0.

In S1: X and Y cannot be 0 b/c x^2>y^2 we cant have 0>0. And we can't have only one equal to zero either because the negative will become positive. Also note that since x^2 (positive number when solved) > y^2 (positive number when solved) |x|>|y| this has to be true.

Suff.


S2: take x=-1 and y=-2 x>y but |x|>|y|?? of course not. you can imagine several values for the opposite though.
GMAT Club Bot
gmatclubot
Re: Re: [#permalink]
10 Jan 2008, 19:45

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions