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

 It is currently 18 Jul 2018, 21:13

### 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

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

# are x and y both positive? A: 2x -2y =1 b: x/y > 1 IMo

Author Message
Manager
Joined: 22 Sep 2008
Posts: 117
are x and y both positive? A: 2x -2y =1 b: x/y > 1 IMo [#permalink]

### Show Tags

05 Oct 2008, 03:33
are x and y both positive?

A: 2x -2y =1
b: x/y > 1

IMo E..

A:
X = -3, Y -3.5 x-y = 0.5 =1/2
X = 3 ,Y =2.5 x-y = 0.5 =1/2
So A is not suff.

B:
x = -3 y = -2 x/y =1 .5 >1
x=3 y =2 x/y = 1.5 >1
So B is not suff.

A +B :
not suff.
E

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Senior Manager
Joined: 21 Apr 2008
Posts: 456
Schools: Kellogg, MIT, Michigan, Berkeley, Marshall, Mellon
Re: are x and y both positive [#permalink]

### Show Tags

05 Oct 2008, 04:06
Well,

My two cents... C

A
X=1, Y=1/2
X=1/2, Y=0
Not suff.

B
X=3, Y=2
X=-3, Y=-2
Not suff.

A+B
from A, X=1/2+Y

in B, (1/2+Y)/y>1; 1/(2Y)+1>1; 1/(2Y)>0, this happens if and only if Y>0, therefore, X>0

My first thought was E, but the GMAT softprep says C, and I had to look for the right solution...

Cheers
_________________

http://gmatclub.com/forum/johnlewis1980-s-profile-feedback-is-more-than-welcome-80538.html

I'm not linked to GMAT questions anymore, so, if you need something, please PM me

I'm already focused on my application package

My experience in my second attempt
http://gmatclub.com/forum/p544312#p544312
My experience in my third attempt
http://gmatclub.com/forum/630-q-47-v-28-engineer-non-native-speaker-my-experience-78215.html#p588275

Retired Moderator
Joined: 05 Jul 2006
Posts: 1734
Re: are x and y both positive [#permalink]

### Show Tags

05 Oct 2008, 07:53
[quote="vr4indian"]are x and y both positive?

A: 2x -2y =1
b: x/y > 1

from a

x-y = 1/2

thus either

x,y +ve or both negative /y/>/x/ or x +ve and y -ve both are tiny fractions........insuff

from 2

x/y> 1 ( both can be +ve or -ve)...insuff however

rewriting x/y> 1 in the form (x-y)/y > 0

both

x-y = 1/2 ( subs in 2) thus (1/2)/y > 0 thus sure y is +ve consiquently x is +ve too

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Re: are x and y both positive   [#permalink] 05 Oct 2008, 07:53
Display posts from previous: Sort by

# are x and y both positive? A: 2x -2y =1 b: x/y > 1 IMo

Moderator: chetan2u

# Events & Promotions

 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®.