Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 20 Jul 2019, 17:56

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Is x*y > 0? (1) x = |y| (2) x*|y| = x*y

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7764
Is x*y > 0? (1) x = |y| (2) x*|y| = x*y  [#permalink]

Show Tags

New post 27 Aug 2018, 06:08
1
4
00:00
A
B
C
D
E

Difficulty:

  85% (hard)

Question Stats:

39% (01:29) correct 61% (01:18) wrong based on 103 sessions

HideShow timer Statistics


Is x*y > 0?

(1) x = |y|
(2) x*|y| = x*y

_________________
Senior Manager
Senior Manager
User avatar
G
Joined: 17 Jan 2017
Posts: 300
Location: India
GPA: 4
WE: Information Technology (Computer Software)
Premium Member
Re: Is x*y > 0? (1) x = |y| (2) x*|y| = x*y  [#permalink]

Show Tags

New post 27 Aug 2018, 07:39
1
chetan2u wrote:
Is x*y > 0?

(1) x = |y|
(2) x*|y| = x*y


We need to find whether both x and y have same sign

Statement1:
|y| is definitely positive or 0
x is positive or 0

Insuff

Statement2:
Case 1:
x is negative and y is positive, xy>0 (False)
Case 2:
x is positive and y is positive, xy>0 (True)
Case 3:
Either x or y is 0, xy>0 (False)

Insuff

Combining both statements still we don't know whether x and y are positive or 0. Hence insuff

Hence E
_________________
Only those who risk going too far, can possibly find out how far one can go
VP
VP
User avatar
D
Status: Learning stage
Joined: 01 Oct 2017
Posts: 1028
WE: Supply Chain Management (Energy and Utilities)
Re: Is x*y > 0? (1) x = |y| (2) x*|y| = x*y  [#permalink]

Show Tags

New post 27 Aug 2018, 07:40
chetan2u wrote:
Is x*y > 0?

(1) x = |y|
(2) x*|y| = x*y



Question stem:- Is x*y > 0

St1:- x = |y| ('x' is non-negative)

So, x*y=|y|*y

Is |y|*y > 0 ?
a) When \(y\geq{0}\), |y|=y. hence \({|y|*y=y^2}\geq{0}\) (here x=|y|=y, so \(x
\geq{0}\))
b) When \(y<0\), |y|=-y. hence {|y|*y}<0
Question stem is inconsistent, therefore insufficient.

St2:- x*|y| = x*y

Subtracting x*y from both the sides, we have
x*|y|-x*y = x*y-x*y
Or, x*|y|-x*y=0
Or, x(|y|-y)=0 (factoring out x)

So, x=0 or |y|-y=0 (Or, |y|=y Or, \(y\geq{0}\))
a) when x=0, x*y=0
b) When y>0, x can be +ve/-ve/0. hence polarity of x*y is inconsistent.
c) When y=0, x*y=0
Insufficient.

Combined, we have \(x\geq{0}\), \(y\geq{0}\) (y<0 is excluded since it dissatisfies st2)
Here also x*y can be zero or positive.
Question stem is still inconsistent.

Ans. (E)
_________________
Regards,

PKN

Rise above the storm, you will find the sunshine
Director
Director
User avatar
G
Joined: 20 Feb 2015
Posts: 790
Concentration: Strategy, General Management
Premium Member
Re: Is x*y > 0? (1) x = |y| (2) x*|y| = x*y  [#permalink]

Show Tags

New post 02 Sep 2018, 09:24
chetan2u wrote:
Is x*y > 0?

(1) x = |y|
(2) x*|y| = x*y



(1) x = |y|

case 1 -- x=0
case 2 --- x = +ve

insufficient

(2) x*|y| = x*y

case 1 --- y=0
case 2 ---y = +ve

insufficient

using both

xy=0
xy>0

insufficient
GMAT Club Bot
Re: Is x*y > 0? (1) x = |y| (2) x*|y| = x*y   [#permalink] 02 Sep 2018, 09:24
Display posts from previous: Sort by

Is x*y > 0? (1) x = |y| (2) x*|y| = x*y

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne