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

 It is currently 06 May 2015, 02:58

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# if xy>0 does (x-1)(y-1) >1 1) X+y=xy 2)x=y I know that

Author Message
TAGS:
Director
Joined: 21 Sep 2004
Posts: 615
Followers: 1

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

if xy>0 does (x-1)(y-1) >1 1) X+y=xy 2)x=y I know that [#permalink]  24 Mar 2005, 16:39
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
if xy>0 does (x-1)(y-1) >1

1) X+y=xy
2)x=y
I know that A is sufficient.. i thought B will be sufficient too. as we are substituting x=y.. why is it not sufficient...
!!!!
Manager
Joined: 05 Feb 2005
Posts: 116
Location: San Jose
Followers: 1

Kudos [?]: 1 [0], given: 0

A.

if xy>0 does (x-1)(y-1) >1

1) X+y=xy
2)x=y
I know that A is sufficient.. i thought B will be sufficient too. as we are substituting x=y.. why is it not sufficient...
!!!!

Putting x=y, LHS = (x-1)^2

Example x = 1, LHS = 0, which is less than 1
x = 3, LHS = 4, which is greater than 1
_________________

Anyone who has never made a mistake has never tried anything new. -Albert Einstein.

VP
Joined: 18 Nov 2004
Posts: 1442
Followers: 2

Kudos [?]: 20 [0], given: 0

"A"

state 1....asking xy-(x+y)+1 > 1...or xy-x-y > 0 ?

if x+y = xy....LHS 0...so ans is NO...suff

state 2.....x = y

y^2-2y > 0

so is y(y-2) > 0 ?

if y < 2.....LHS is < 0....if y > 2...LHS is > 0....insuff
Similar topics Replies Last post
Similar
Topics:
4 If xy > 0, does (x - 1)(y - 1) = 1? 5 09 Feb 2014, 23:30
If xy > 0, does (x-1)(y-1) = 1? 2 03 Dec 2010, 21:47
8 If xy > 0 does (x-1)(y-1)=1 ? 19 03 Aug 2010, 04:25
xy >0 does (x-1)(y-1) =1 x+y=xy x=y spoiler below the 4 07 Aug 2007, 13:40
if xy > 0, does (x - 1)(y - 1) = 1 ? (1) x + y = xy (2) x 3 25 Oct 2006, 07:33
Display posts from previous: Sort by