GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 28 Mar 2020, 22:46

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

If xy = -6, what is the value of xy(x+y)?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Manager
Manager
User avatar
P
Status: wake up with a purpose
Joined: 24 Feb 2017
Posts: 196
Concentration: Accounting, Entrepreneurship
GMAT ToolKit User Premium Member
If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 21:02
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

53% (01:20) correct 47% (01:28) wrong based on 15 sessions

HideShow timer Statistics

If xy = -6, what is the value of xy(x+y)?

(1) x - y = 5

(2) xy^2 = 18

_________________
If people are NOT laughing at your GOALS, your goals are SMALL.
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 8297
If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 21:42
If xy = -6, what is the value of xy(x+y)?

(1) x - y = 5
So xy=-6 and x-y=5 or x=y+5, but we can have different values..
\(xy=-6....(y+5)y=-6....y^2+5y+6=0......y^2+2y+3y+6=0....(y+2)(y+3)=0\)
So y can be -2, hence x=3 and \(xy(x+y)=-6(3-2)=-6\)
y can be -3, hence x=2 and \(xy(x+y)=-6(2-3)=6\)
Insuff

(2) \(xy^2 = 18...xy*y=18....-6*y=18...y=-3\)
hence x=2 and \(xy(x+y)=-6(2-3)=6\)
Suff

B
_________________
Intern
Intern
avatar
B
Joined: 14 Mar 2019
Posts: 9
Location: India
GPA: 4
Re: If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 21:44
1. (x-y)^2= (x+y)^2 -4xy
(X+y)^2= 25+4xy = 25-4*-6 = 25-24=1
X+y =1 or x+y = -1
Not sufficient

2. Xy^2=18
Xy*y=18
-6*y=18
Y=-3
X=2
X+y=-1
Sufficient
Ans B

Posted from my mobile device
Director
Director
User avatar
V
Joined: 06 Jan 2015
Posts: 744
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 22:37
Quote:
If xy = -6, what is the value of xy(x+y)?

(1) x - y = 5

(2) xy^2 = 18


HI chetan2u, VeritasKarishma, Bunuel, GMATBusters, GMATPrepNow, EgmatQuantExpert, GMATinsight , GMATGuruNY, MentorTutoring

Is it not advisable to use the numbers in these kinds of problems?

If xy = -6 there multiple possibilities with integers 6,1 & 2,3 with sign changes.Little but confused using algebra into the questions.

Below is the link to the Gmatclub test question.

https://gmatclub.com/forum/d01-183504.html
_________________
आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution
Retired Moderator
User avatar
V
Joined: 27 Oct 2017
Posts: 1555
Location: India
Concentration: International Business, General Management
GPA: 3.64
WE: Business Development (Energy and Utilities)
CAT Tests
If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 23:20
It depends on how quick you are at numbers picking.

for xy = - 6, we can have (x,y) can be (-1,6) , (6,-1), (3,-2), (2,-3)... and many other values
but (3,-2), (2,-3) satisfy St 1 : x-y = 5

and (3,-2), (2,-3) gives 2 different answer for xy(x+y)

So, St1 is not sufficient.

Thus Number picking seems a bit more difficult.

Also, I would recommend practicing more Algebra, because Algebra is unavoidable and will be used for other questions also.


NandishSS wrote:
Quote:
If xy = -6, what is the value of xy(x+y)?

(1) x - y = 5

(2) xy^2 = 18


HI chetan2u, VeritasKarishma, Bunuel, GMATBusters, GMATPrepNow, EgmatQuantExpert, GMATinsight , GMATGuruNY, MentorTutoring

Is it not advisable to use the numbers in these kinds of problems?

If xy = -6 there multiple possibilities with integers 6,1 & 2,3 with sign changes.Little but confused using algebra into the questions.

Below is the link to the Gmatclub test question.

https://gmatclub.com/forum/d01-183504.html

_________________
Director
Director
User avatar
V
Joined: 06 Jan 2015
Posts: 744
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
Re: If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 23:51
HI RashedVai

This question is discussed in the below link.

Bunuel FYI

https://gmatclub.com/forum/if-xy-6-what ... 67646.html
_________________
आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution
Director
Director
User avatar
V
Joined: 06 Jan 2015
Posts: 744
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
Re: If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 22 Feb 2020, 23:54
GMATBusters wrote:
It depends on how quick you are at numbers picking.

for xy = - 6, we can have (x,y) can be (-1,6) , (6,-1), (3,-2), (2,-3)... and many other values
but (3,-2), (2,-3) satisfy St 1 : x-y = 5

and (3,-2), (2,-3) gives 2 different answer for xy(x+y)

So, St1 is not sufficient.

Thus Number picking seems a bit more difficult.

Also, I would recommend practicing more Algebra, because Algebra is unavoidable and will be used for other questions also.


NandishSS wrote:
Quote:
If xy = -6, what is the value of xy(x+y)?

(1) x - y = 5

(2) xy^2 = 18


HI chetan2u, VeritasKarishma, Bunuel, GMATBusters, GMATPrepNow, EgmatQuantExpert, GMATinsight , GMATGuruNY, MentorTutoring

Is it not advisable to use the numbers in these kinds of problems?

If xy = -6 there multiple possibilities with integers 6,1 & 2,3 with sign changes.Little but confused using algebra into the questions.

Below is the link to the Gmatclub test question.

https://gmatclub.com/forum/d01-183504.html


Thank you GMATBusters , Will practice using Algebra as well :-)
_________________
आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 62287
Re: If xy = -6, what is the value of xy(x+y)?  [#permalink]

Show Tags

New post 23 Feb 2020, 02:43
GMAT Club Bot
Re: If xy = -6, what is the value of xy(x+y)?   [#permalink] 23 Feb 2020, 02:43
Display posts from previous: Sort by

If xy = -6, what is the value of xy(x+y)?

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





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