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

It is currently 01 Aug 2015, 22:32
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the value of xy?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Intern
Intern
avatar
Joined: 12 Nov 2009
Posts: 11
Followers: 0

Kudos [?]: 3 [1] , given: 2

What is the value of xy? [#permalink] New post 04 Jan 2010, 00:37
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

79% (01:34) correct 21% (00:22) wrong based on 14 sessions
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.
1 KUDOS received
Senior Manager
Senior Manager
avatar
Joined: 30 Aug 2009
Posts: 286
Location: India
Concentration: General Management
Followers: 3

Kudos [?]: 116 [1] , given: 5

Re: What is the value of xy? [#permalink] New post 04 Jan 2010, 07:18
1
This post received
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
Intern
avatar
Joined: 12 Nov 2009
Posts: 11
Followers: 0

Kudos [?]: 3 [0], given: 2

Re: What is the value of xy? [#permalink] New post 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.
2 KUDOS received
Manager
Manager
avatar
Status: Meh, I can't take the GMAT before 2017.
Joined: 20 Aug 2011
Posts: 145
Followers: 3

Kudos [?]: 73 [2] , given: 0

Re: What is the value of xy? [#permalink] New post 05 Jan 2012, 19:49
2
This post received
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
Manager
User avatar
Joined: 29 Jul 2011
Posts: 108
Location: United States
Followers: 4

Kudos [?]: 44 [0], given: 6

Re: What is the value of xy? [#permalink] New post 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
Intern
avatar
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] New post 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
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5709
Followers: 323

Kudos [?]: 63 [0], given: 0

Premium Member
Re: What is the value of xy? [#permalink] New post 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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: What is the value of xy?   [#permalink] 27 Jul 2015, 07:30
    Similar topics Author Replies Last post
Similar
Topics:
9 Experts publish their posts in the topic What is the value of xy? Bunuel 6 12 Jul 2014, 15:09
3 Experts publish their posts in the topic What is the value of xy? swati007 4 05 Mar 2014, 19:12
Experts publish their posts in the topic What is the value of xy? Bunuel 3 06 Feb 2014, 00:37
Experts publish their posts in the topic What is the value of xy ? avohden 2 24 Oct 2013, 16:10
What is the value of xy? shawndx 0 07 Jan 2012, 02:15
Display posts from previous: Sort by

What is the value of xy?

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.