GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 20 Sep 2018, 09:49

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

What is the value of (a+b)^2?

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

Hide Tags

Manager
Manager
User avatar
Joined: 28 May 2009
Posts: 151
Location: United States
Concentration: Strategy, General Management
GMAT Date: 03-22-2013
GPA: 3.57
WE: Information Technology (Consulting)
GMAT ToolKit User
What is the value of (a+b)^2?  [#permalink]

Show Tags

New post 24 Dec 2012, 18:59
1
1
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

77% (00:55) correct 23% (01:06) wrong based on 141 sessions

HideShow timer Statistics

What is the value of (a+b)^2?

(1) ab = 0
(2) (a-b)^2 = 36

_________________

New to GMAT Club? Start here

Kindle Flashcards - Quant (Official Gmat Club, miguemick's Quant topics), and Verbal (Official Gmat Club) - in Kindle (azw3) format

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49271
Re: What is the value of (a+b)^2?  [#permalink]

Show Tags

New post 25 Dec 2012, 05:02
1
megafan wrote:
What is the value of (a+b)^2?

(1) ab = 0
(2) (a-b)^2 = 36


Each statement alone is clearly insufficient. When we take the statements together we have: ab=0 and a^2-2ab+b^2=36, thus a^2+b^2=36 --> (a+b)^2=a^2+2ab+b^2=36+0=36. Sufficient.

Answer: C.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

EMPOWERgmat Instructor
User avatar
V
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12415
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: What is the value of (a+b)^2?  [#permalink]

Show Tags

New post 14 May 2015, 22:41
Hi All,

This question can be solved with Algebra (and recognizing Classic Quadratics) or by TESTing VALUES.

We're asked for the value of (A+B)^2

Fact 1: AB = 0

This means that either A or B or Both = 0

IF...
A = 0
B = 0
(0+0)^2 = 0

IF....
A = 1
B = 0
(1+0)^2 = 1
Fact 1 is INSUFFICIENT

Fact 2: (A-B)^2 = 36

This ultimately means that (A-B) = 6 or -6

IF.....
A = 6
B = 0
(6+0)^2 = 36

IF....
A = 7
B = 1
(7+1)^2 = 64
Fact 2 is INSUFFICIENT

Combined, we know....
A or B or Both = 0
(A-B) = 6 or -6

IF....
A = 0
B = 6 OR -6
(0+6)^2 = (0-6)^2 = 36

IF....
B = 0
A = 6 OR -6
(0+6)^2 = (0-6)^2 = 36

The answer is ALWAYS 36.
Combined, SUFFICIENT

Final Answer:

GMAT assassins aren't born, they're made,
Rich
_________________

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Manager
Manager
avatar
Joined: 09 Jan 2013
Posts: 76
Concentration: Entrepreneurship, Sustainability
GMAT 1: 650 Q45 V34
GMAT 2: 740 Q51 V39
GRE 1: Q790 V650
GPA: 3.76
WE: Other (Pharmaceuticals and Biotech)
Reviews Badge
Re: What is the value of (a+b)^2?  [#permalink]

Show Tags

New post 15 May 2015, 09:46
\((a+b)^2= a^2+b^2+2ab\)

St1
ab=0
=> either a=0 or b=0 or both.
=> \((a+b)^2= a^2+b^2\)
Since we cant determine this value. Insufficient

St2
(\(a-b)^2=36\)
=>\(a^2+b^2-2ab=36\)
Insufficient

St1+St2
since ab=0, \((a-b)^2=a^2+b^2=36 = (a+b)^2\)
Sufficient

Answer C.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8106
Premium Member
Re: What is the value of (a+b)^2?  [#permalink]

Show Tags

New post 20 Jul 2018, 00:58
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 (a+b)^2? &nbs [#permalink] 20 Jul 2018, 00:58
Display posts from previous: Sort by

What is the value of (a+b)^2?

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

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.