BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

DS question from GMATprep!

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Mon Jul 02, 2007 4:18 pm

by jay2007 » Wed Jul 11, 2007 10:25 am
Is the answer C?

1) 2x-2y = 1
x-y = 1/2
Possible values are: x = 0, y=-1/2
x=1, y=1/2
So, we can't say.
2) x/y > 1
x>y
- Can't say

Combining 1 & 2
- x and y are positive.
Top
Junior | Next Rank: 30 Posts
Posts: 17
Joined: Fri Jun 08, 2007 7:56 am

by owodee » Wed Jul 11, 2007 10:35 am
Jay,

from x-y= 1/2, x could be -4.5 and y could be -5 and x-y would still equal 1/2. I am not sure if your logic for (1) is right
Top
Senior | Next Rank: 100 Posts
Posts: 50
Joined: Mon Jul 02, 2007 4:18 pm

by jay2007 » Wed Jul 11, 2007 10:50 am
you are right. The answer has to be E. right?
Top
User avatar
Community Manager
Posts: 789
Joined: Sun Jan 28, 2007 3:51 pm
Location: Silicon valley, California
Thanked: 30 times
Followed by:1 members

Re: DS question from GMATprep!

by jayhawk2001 » Wed Jul 11, 2007 9:15 pm
owodee wrote:Are x and y both positive?

(1) 2x - 2y = 1

(2) x/y > 1

OA after a few replies
Is it C ?

1 - insufficient. Multiple values of x and y satisfy x-y = 1/2

2 - insufficient. x and y can be either both positive or both negative.

Together,

x - y = 1/2
Dividing both sides by y

x/y - 1 = 1/2y

We know x/y > 1 and so left side of the eqn is positive. This implies
1/2y is positive and so y is positive.

If x/y > 1 and y is positive, then x has to be positive.

So C ?
Top
Junior | Next Rank: 30 Posts
Posts: 17
Joined: Fri Jun 08, 2007 7:56 am

by owodee » Thu Jul 12, 2007 4:23 am
Wow, thanks a lot jayhawk, I dont think I would have thought of that.

The answer OA is C.
Top
Post new topic Post Reply
• Page 1 of 1