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

It is currently 20 Oct 2014, 18:46

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is Y? 1. y^3 + 2y = y + 2y^2 2. y^2 = y

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 08 Sep 2010
Posts: 171
Followers: 0

Kudos [?]: 15 [0], given: 18

What is Y? 1. y^3 + 2y = y + 2y^2 2. y^2 = y [#permalink] New post 04 Jul 2011, 07:02
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

80% (01:45) correct 20% (01:34) wrong based on 5 sessions
What is Y?

1. y^3 + 2y = y + 2y^2

2. y^2 = y
[Reveal] Spoiler: OA

_________________

My will shall shape the future. Whether I fail or succeed shall be no man's doing but my own.

If you like my explanations award kudos.

Manager
Manager
User avatar
Joined: 29 Jun 2011
Posts: 76
Followers: 3

Kudos [?]: 11 [0], given: 47

Re: What is y ? [#permalink] New post 04 Jul 2011, 07:08
easy :
take statement 2 : y^2 = y => y = 0 or 1 => statement is not sufficient
take statement 1 : y^3 + 2y = y + 2y^2 => y = 0 or 1 => statement is not sufficient
take both together : y = 0 or y =1 => statements is not sufficient together
Ans E

any doubt? ask
_________________

It matters not how strait the gate,
How charged with punishments the scroll,
I am the master of my fate :
I am the captain of my soul.
~ William Ernest Henley

SVP
SVP
avatar
Joined: 16 Nov 2010
Posts: 1691
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 30

Kudos [?]: 297 [0], given: 36

Premium Member Reviews Badge
Re: What is y ? [#permalink] New post 04 Jul 2011, 07:09
(1) says :

y^3 + 2y = y + 2y^2

=> y^3 - 2y^2 + y = 0

=> y(y^2 - 2y + 1) = 0

=> y(y-1)^2 = 0

So y = 0, or y = 1

Insufficient

(2) says :

y^2 = y

=> y(y-1) = 0

=> y = 0 or y = 1

Insufficient

(1) + (2)

y = 0 or y = 1

Insufficient


Answer - E
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
avatar
Joined: 11 Sep 2010
Posts: 13
Location: India
GMAT 1: 620 Q49 V25
Followers: 0

Kudos [?]: 5 [0], given: 0

Re: What is y ? [#permalink] New post 04 Jul 2011, 07:14
puneetj wrote:
What is Y?

1. y^3 + 2y = y + 2y^2

2. y^2 = y


1. y^3 + 2y = y + 2y^2
y^3 + 2y - y - 2y^2 = 0
y(y^2 + 1 - 2y) = 0
y = 0 or y-1=0 => y=1

Cant conclude

2. y^2 - y = 0
y(y-1) = 0
y = 0 or y-1=0 => y=1

Cant conclude

Together also can't conclude hence E.

We cannot cancel y on both side as it not known whether it is -ve or +ve.
Manager
Manager
avatar
Joined: 08 Sep 2010
Posts: 171
Followers: 0

Kudos [?]: 15 [0], given: 18

Re: What is y ? [#permalink] New post 04 Jul 2011, 07:16
Thanks...i realize my mistake. Did not pay attention to the 1st equation...:(

This is what I did..

y^3 + 2y = y + 2y^2
y(y^2 + 2) = y(1 + 2y)

Then cancelled the y on both sides ....big mistake
_________________

My will shall shape the future. Whether I fail or succeed shall be no man's doing but my own.

If you like my explanations award kudos.

Re: What is y ?   [#permalink] 04 Jul 2011, 07:16
    Similar topics Author Replies Last post
Similar
Topics:
What is the value of x^2 + y^2 ? (1) x^2+ y^2 = 2xy + 1 (2) dreambeliever 4 05 Jun 2011, 08:16
What is the value of x^2 + y^2? 1) x^2 + y^2 = 2xy + 1 2) youven 6 24 Jul 2010, 07:50
1 If X^3Y = 24 , what is the value of X^3Y^3 X^2Y^2 ? (1) Hussain15 10 20 Apr 2010, 06:27
What is the value of x^2 + y^2? (1) x^2 + y^2 = 2xy +1 (2) lumone 1 28 Jan 2009, 10:57
What is y? 1. y^3 + 2y = y + 2*y^2 2. y^2 = y bmwhype2 6 18 Oct 2007, 13:18
Display posts from previous: Sort by

What is Y? 1. y^3 + 2y = y + 2y^2 2. y^2 = y

  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®.