What is the value of xy? : GMAT Data Sufficiency (DS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 20 Jan 2017, 00:16

### 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

# What is the value of xy?

Author Message
TAGS:

### Hide Tags

Intern
Joined: 12 Nov 2009
Posts: 11
Followers: 0

Kudos [?]: 4 [1] , given: 2

What is the value of xy? [#permalink]

### Show Tags

04 Jan 2010, 00:37
1
KUDOS
00:00

Difficulty:

25% (medium)

Question Stats:

72% (01:56) correct 28% (00:52) wrong based on 178 sessions

### HideShow timer Statistics

What is the value of xy?

(1) y = x + 1
(2) y = x^2 + 1
[Reveal] Spoiler: OA

Last edited by Bunuel on 27 Jul 2015, 07:28, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
Senior Manager
Joined: 30 Aug 2009
Posts: 286
Location: India
Concentration: General Management
Followers: 3

Kudos [?]: 162 [1] , given: 5

Re: What is the value of xy? [#permalink]

### Show Tags

04 Jan 2010, 07:18
1
KUDOS
gouribhalerao wrote:
Hi,

I have a doubt in one data sufficiency question of mba.com test. Can anyone please explain? The question is as follows.

What is the value of xy?
1. y = x + 1
2. y = x^2 + 1

stmnt1 - y = x+1 will not help us to get value of xy as we do not know the value of x. hence insuff
stmnt2 - y = x^2 + 1 same as 1. hence insuff

taking together we get x+ 1 = x^2 + 1 . we get x^2 = x . here x can be both 1 or 0
so we will get 2 different values for xy and even together both are not sufficient.

will go with E
Intern
Joined: 12 Nov 2009
Posts: 11
Followers: 0

Kudos [?]: 4 [0], given: 2

Re: What is the value of xy? [#permalink]

### Show Tags

04 Jan 2010, 07:40
That's right. Thanks.
While solving the exam, I thought that if I consider both statements together, then x^2 = x. Then dividing both sides by x, I can get x=1. But yes, when here x can either be 0 or 1 and that changes the answer.
Manager
Joined: 20 Aug 2011
Posts: 146
Followers: 3

Kudos [?]: 95 [2] , given: 0

Re: What is the value of xy? [#permalink]

### Show Tags

05 Jan 2012, 19:49
2
KUDOS
Question is- can you find the exact value of xy.

1.
y=x+1
there is no way to determine value of x or y.
x can be a fraction, positive/negative integer.

Insufficient.

2.
y=x^2+1
all we know that y is positive.
Insufficient.

1+2
x+1=x^2+1
x^2=x
x is 0 or 1
y is 1 or 2

xy=0 or 2.
Insufficient

Hence E
Manager
Joined: 29 Jul 2011
Posts: 107
Location: United States
Followers: 5

Kudos [?]: 58 [0], given: 6

Re: What is the value of xy? [#permalink]

### Show Tags

06 Jan 2012, 17:57
1. y=x+1. multiply both sides by x -> xy=x(x+1). No info on x, insuff.
2. y=x^2+1. multiply both sides by x -> xy=x(x^2+1). No info on x, insuff.

Together, equating both statements -> x+1 = x^2+1 -> x = 0, 1
Substituting gives y = 1,2.

Two solutions for xy -> E.
_________________

I am the master of my fate. I am the captain of my soul.
Please consider giving +1 Kudos if deserved!

DS - If negative answer only, still sufficient. No need to find exact solution.
PS - Always look at the answers first
CR - Read the question stem first, hunt for conclusion
SC - Meaning first, Grammar second
RC - Mentally connect paragraphs as you proceed. Short = 2min, Long = 3-4 min

Intern
Joined: 07 Jan 2012
Posts: 7
Location: United States
WE: Marketing (Other)
Followers: 0

Kudos [?]: 6 [0], given: 0

Re: What is the value of xy? [#permalink]

### Show Tags

07 Jan 2012, 02:15
Statement 1 and 2 considered individually are clearly insufficient. When we combine these two, we get two solutions as below:

x^2-x=0
x(x-1)=0
x=0 OR x=1

X=0, Y=1, XY = 0
X = 1, Y=2, XY = 2

Thus we have two solutions here and answer is E
GMAT Club Legend
Joined: 09 Sep 2013
Posts: 13459
Followers: 575

Kudos [?]: 163 [0], given: 0

Re: What is the value of xy? [#permalink]

### Show Tags

27 Jul 2015, 07:30
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Senior Manager
Status: Exam scheduled!!
Joined: 05 Sep 2016
Posts: 411
Location: United States (WI)
Concentration: Marketing, Technology
WE: Other (Law)
Followers: 3

Kudos [?]: 13 [0], given: 242

Re: What is the value of xy? [#permalink]

### Show Tags

18 Sep 2016, 16:29

(1) y = x+1

NOT SUFFICIENT - we're not able to gather what x and y equals

(2) y = x^2 +1

NOT SUFFICIENT - same as (1)

Together - (1) + (2) --> x+1 = x^2 + 1

NOT SUFFICIENT
Re: What is the value of xy?   [#permalink] 18 Sep 2016, 16:29
Similar topics Replies Last post
Similar
Topics:
10 What is the value of xy? 8 12 Jul 2014, 15:09
3 What is the value of xy? 4 05 Mar 2014, 19:12
23 If xy = - 6, what is the value of xy(x+y)? 15 18 Feb 2014, 02:52
What is the value of xy? 3 06 Feb 2014, 00:37
What is the value of xy ? 2 24 Oct 2013, 16:10
Display posts from previous: Sort by