Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
May 1212:00 PM EDT
-11:59 PM EDT
Make the most of your break with the most realistic GMAT™ prep. Take up to $700 off select products.
May 1308:30 AM PDT
-09:30 AM PDT
In Episode 4 of our GMAT Ninja CR series, we tackle the most intimidating CR question type: Boldface & "Legalese" questions. If you've ever stared at an answer choice that reads, "The first is a consideration introduced to counter a position that...- May 14
08:30 AM PDT
-09:30 AM PDT
Most GMAT test-takers are intimidated by the hardest GMAT Verbal questions. In this session, Target Test Prep GMAT instructor Erika Tyler-John, a 100th percentile GMAT scorer, will show you how top scorers break down challenging Verbal questions..
18 Jun 2007, 19:37
Kudos
Bookmarks
Is xy > x/y?
(1) xy > 0
(2) y < 0
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is
sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
OA - 'E'
(1) xy > 0
(2) y < 0
A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is
sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.
OA - 'E'
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
18 Jun 2007, 19:49
Kudos
Bookmarks
1) any two positive numbers or any two negative numbers will give you >0. You can make X=2 and Y=1 and it doesnt work.
Since:
2 x 1 = 2 / 1
2=2 which doesnt meet the criteria of greater than
2) just use the same numbers as above (y=-1 which is <0) but make both negative and you get the same result.
The solution for 2) also proves that together they dont work since -2 x -1 = 2 which meets the requirements for 1) but is also is equal to -2 / -1 and not greater than.
Since:
2 x 1 = 2 / 1
2=2 which doesnt meet the criteria of greater than
2) just use the same numbers as above (y=-1 which is <0) but make both negative and you get the same result.
The solution for 2) also proves that together they dont work since -2 x -1 = 2 which meets the requirements for 1) but is also is equal to -2 / -1 and not greater than.
18 Jun 2007, 23:19
Kudos
Bookmarks
(E) for me 
xy > x/y?
x*y - x/y > 0 ?
x*(y-1/y) > 0 ?
x*((y^2-1)/y) > 0 ?
x*(y+1)*(y-1)/y > 0 ?
From 1
xy > 0
sgn(x) = sgn(y)
Then,
sign(x*(y+1)*(y-1)/y)
= sign(x)*sign(y+1)*sign(y-1)/sign(y)
= sign(y+1)*sign(y-1)
So,
o If y > 0 then, y+1 > 1 > 0 and y-1 > -1... sign(x*(y+1)*(y-1)/y) = sign(y-1) which could be positive or negative
o If y < 0 then, y+1 < 1 and y-1 < -1 < 0... sign(x*(y+1)*(y-1)/y) = sign(y+1) which could be positive or negative
INSUFF.
From 2
y < 0
We have no clue about x.
INSUFF.
Both 1 & 2
We are in the second case of stat 1 : y < 0
Implying that:
sign(x*(y+1)*(y-1)/y) = sign(y+1) which could be positive or negative
INSUFF.
xy > x/y?
x*y - x/y > 0 ?
x*(y-1/y) > 0 ?
x*((y^2-1)/y) > 0 ?
x*(y+1)*(y-1)/y > 0 ?
From 1
xy > 0
sgn(x) = sgn(y)
Then,
sign(x*(y+1)*(y-1)/y)
= sign(x)*sign(y+1)*sign(y-1)/sign(y)
= sign(y+1)*sign(y-1)
So,
o If y > 0 then, y+1 > 1 > 0 and y-1 > -1... sign(x*(y+1)*(y-1)/y) = sign(y-1) which could be positive or negative
o If y < 0 then, y+1 < 1 and y-1 < -1 < 0... sign(x*(y+1)*(y-1)/y) = sign(y+1) which could be positive or negative
INSUFF.
From 2
y < 0
We have no clue about x.
INSUFF.
Both 1 & 2
We are in the second case of stat 1 : y < 0
Implying that:
sign(x*(y+1)*(y-1)/y) = sign(y+1) which could be positive or negative
INSUFF.
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
