DS : GMAT PREP

This topic has expert replies
Source: — Data Sufficiency |

User avatar
Legendary Member
Posts: 588
Joined: Sun Oct 16, 2011 9:42 am
Location: New Delhi, India
Thanked: 130 times
Followed by:9 members
GMAT Score:720

by rijul007 » Mon Nov 07, 2011 1:03 am
1) x/y = 1

x = y

Doesnt tell us anything about the value of x

Insufficient

2) xy = 1


x = 1/y

Again doesnt tell us anything about the value of x


Insufficient

Combining both the statements

x/y = xy = 1

1/y = y
y^2 = 1
y = 1 [ y greater than 0]

x/y = 1
x = 1

Option C

User avatar
Community Manager
Posts: 1060
Joined: Fri May 13, 2011 6:46 am
Location: Utrecht, The Netherlands
Thanked: 318 times
Followed by:52 members

by neelgandham » Mon Nov 07, 2011 1:03 am
If x and y are greater than 0, is x = 1?

1) x/y = 1; (x,y) can take infinite number of values such as (1,1),(2,2),(3,3),(4,4).. Insufficient
2) xy = 1; (x,y) can take infinite number of values such as (1,1), (2,0.5), (3, 0.33).. Insufficient

From 1 and 2 we get x = y = 1 Sufficient Ans C
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/

User avatar
Master | Next Rank: 500 Posts
Posts: 489
Joined: Tue Jul 05, 2011 11:10 am
Thanked: 28 times
Followed by:5 members

by gmatblood » Mon Nov 07, 2011 1:05 am
IMO: E

from 1, x=y
from 2, xy = 1

from 1 and 2) x and y can be either -1 or 1.

User avatar
Legendary Member
Posts: 588
Joined: Sun Oct 16, 2011 9:42 am
Location: New Delhi, India
Thanked: 130 times
Followed by:9 members
GMAT Score:720

by rijul007 » Mon Nov 07, 2011 1:14 am
gmatblood wrote:IMO: E

from 1, x=y
from 2, xy = 1

from 1 and 2) x and y can be either -1 or 1.

Its already given in the ques, x and y are greater than 0.
If x and y are greater than 0, is x = 1?
1) x/y = 1
2) xy = 1

User avatar
Master | Next Rank: 500 Posts
Posts: 489
Joined: Tue Jul 05, 2011 11:10 am
Thanked: 28 times
Followed by:5 members

by gmatblood » Mon Nov 07, 2011 1:19 am
rijul007 wrote:
gmatblood wrote:IMO: E

from 1, x=y
from 2, xy = 1

from 1 and 2) x and y can be either -1 or 1.

Its already given in the ques, x and y are greater than 0.
If x and y are greater than 0, is x = 1?
1) x/y = 1
2) xy = 1
my bad :( :(