It is currently 22 Feb 2018, 10:47

TODAY:

MIT Sloan Releasing 1st Wave of Interview Invites - Join GMATClub CHAT for Live Updates


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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is a=b?

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

Hide Tags

Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 4904
GPA: 3.82
Is a=b? [#permalink]

Show Tags

New post 24 Feb 2017, 01:15
Expert's post
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

78% (00:28) correct 22% (00:22) wrong based on 49 sessions

HideShow timer Statistics

Is a=b?

1) \(a^2=b^2\)
2) \(a=2\)
[Reveal] Spoiler: OA

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo


Last edited by Bunuel on 24 Feb 2017, 07:01, edited 1 time in total.
Edited the OA.
GMAT Forum Moderator
avatar
D
Joined: 27 May 2014
Posts: 429
GMAT 1: 730 Q49 V41
GMAT ToolKit User Premium Member
Re: Is a=b? [#permalink]

Show Tags

New post 24 Feb 2017, 02:48
(1) a^2 = b^2;
Suppose, a = 2, and b = 2, Therefore, a = b;

Again, suppose a= 2 and b = -2; In this case also a^2 = b^2 is true, but a ≠ b; Hence, Insufficient.

(2) a = 2; Insufficient;

(1) And (2) together, Insufficient;

Answer E.
Senior Manager
Senior Manager
avatar
P
Joined: 06 Jan 2015
Posts: 321
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
Re: Is a=b? [#permalink]

Show Tags

New post 24 Feb 2017, 06:45
MathRevolution wrote:
Is a=b?

1) \(a^2=b^2\)
2) \(a=2\)


Hi Bunuel

Can throw some light on this question

Seems like ans is E. Can you validate.
_________________

आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution

Intern
Intern
avatar
Joined: 24 Feb 2017
Posts: 2
GMAT ToolKit User
Re: Is a=b? [#permalink]

Show Tags

New post 24 Feb 2017, 06:50
MathRevolution wrote:
Is a=b?

1) \(a^2=b^2\)
2) \(a=2\)


In statement 1, If a^2 = b^2, then b can be equal to a or b can be equal to -a because a^2 is also equal to (-a)^2. Hence insufficient
In statement 2, a = 2, but there is no information of b. Hence, insufficient

By combining, if a = 2, then a^2 is 4. But b can be 2 or -2 because 2^2 = 4 and (-2)^2 is also 4.

Hence, together also insufficient.

Thanks,
Anant Saraogi
Expert Post
Top Contributor
SVP
SVP
User avatar
P
Joined: 11 Sep 2015
Posts: 2058
Location: Canada
Re: Is a=b? [#permalink]

Show Tags

New post 24 Feb 2017, 06:53
Expert's post
Top Contributor
NandishSS wrote:
MathRevolution wrote:
Is a=b?

1) \(a^2=b^2\)
2) \(a=2\)


Hi Bunuel

Can throw some light on this question

Seems like ans is E. Can you validate.


You're right; the correct answer is E

Statements 1 and 2 combined
Case a: a = 2 and b = 2, in which case a EQUALS b
Case b: a = 2 and b = -2, in which case a DOES NOT EQUAL b
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Senior Manager
Senior Manager
avatar
P
Joined: 06 Jan 2015
Posts: 321
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
Re: Is a=b? [#permalink]

Show Tags

New post 24 Feb 2017, 17:34
GMATPrepNow wrote:
NandishSS wrote:
MathRevolution wrote:
Is a=b?

1) \(a^2=b^2\)
2) \(a=2\)


Hi Bunuel

Can throw some light on this question

Seems like ans is E. Can you validate.


You're right; the correct answer is E

Statements 1 and 2 combined
Case a: a = 2 and b = 2, in which case a EQUALS b
Case b: a = 2 and b = -2, in which case a DOES NOT EQUAL b
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Cheers,
Brent

Thank you Brent :-)

Sent from my AO5510 using GMAT Club Forum mobile app
_________________

आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution

Expert Post
Math Revolution GMAT Instructor
User avatar
D
Joined: 16 Aug 2015
Posts: 4904
GPA: 3.82
Re: Is a=b? [#permalink]

Show Tags

New post 26 Feb 2017, 20:32
==> In the original condition, there are 2 variables (a,b) and in order to match the number of variables to the number of equations, there must be 2 equations. Since there is 1 for con 1) and 1 for con 2), C is most likely to be the answer. By solving con 1) and con 2), from a=2, you get \(b^2=2^2=4\), then b=±2. Thus, (a,b)=(2,2) yes but (a,b)=(2,-2) no, hence it is not sufficient.

The answer is E.
Answer: E
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Re: Is a=b?   [#permalink] 26 Feb 2017, 20:32
Display posts from previous: Sort by

Is a=b?

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


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

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

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®.