Apr 23 08:00 PM EDT  09:00 PM EDT Strategies and techniques for approaching featured GMAT topics. Tuesday, April 23rd at 8 pm ET Apr 23 10:00 PM PDT  11:00 PM PDT Learn the best strategies for acing the Verbal section. From Sentence Correction tactics to 3 keys for solving Reading Comprehension questions and tips for Critical Reasoning questions. Video Premiere April 23rd at 8am PT Apr 24 08:00 AM PDT  09:00 AM PDT Join the Live Chat April 24th at 8 am PT. Learn the best strategies for acing the Verbal section. From Sentence Correction tactics to 3 keys for solving Reading Comprehension questions and tips for Critical Reasoning questions. Apr 24 08:00 PM EDT  09:00 PM EDT Maximize Your Potential: 5 Steps to Getting Your Dream MBA Part 3 of 5: Key TestTaking Strategies for GMAT. Wednesday, April 24th at 8 pm ET Apr 25 10:00 PM PDT  11:00 PM PDT Join an exclusive workshop for GMAT Club members and learn how to cut your preparation time by 50% and still reach a 700+ on the GMAT. Limited for the first 99 registrants. Register today! Apr 27 07:00 AM PDT  09:00 AM PDT Attend this webinar and master GMAT SC in 10 days by learning how meaning and logic can help you tackle 700+ level SC questions with ease. Apr 28 07:00 AM PDT  09:00 AM PDT Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes. Apr 29 08:00 AM PDT  09:00 AM PDT Join a free live webinar and learn timemanagement tactics that will guarantee you answer all questions, in all sections, on time. Save your spot today! May 01 10:00 PM PDT  11:00 PM PDT Target Test Prep is kicking off spring with a fresh giveaway contest! For a limited time, you have a chance to win 4 months of full, FREE access to our 5star rated GMAT Quant course.
Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 20 Apr 2010
Posts: 28

What is the value of a?
[#permalink]
Show Tags
31 Aug 2010, 14:46
Question Stats:
69% (00:37) correct 31% (01:08) wrong based on 155 sessions
HideShow timer Statistics
What is the value of a? (1) a  b + 4 = 0 (2) a = a Since "a" = a, 2a = 0, or a = 0 Am I missing something here? How does 2a = 0? Confused about this one, given that a is an unknown variable. Thanks
Official Answer and Stats are available only to registered users. Register/ Login.



Manager
Joined: 16 Feb 2010
Posts: 175

Re: What is the value of a?
[#permalink]
Show Tags
31 Aug 2010, 15:02
source? cannt understand why 2a = 0, but my understanding is that only 0 satisfies a = a , try plugging positive, negative and fractions in the place of a....



Intern
Joined: 20 Apr 2010
Posts: 28

Re: What is the value of a?
[#permalink]
Show Tags
31 Aug 2010, 16:13
Source is the ARCO GMAT/GRE book. I don't understand how a = 0 To me (intuitively) if a is positive, a is negative, and if a is negative, a is positive. Hrumphhhh!



Joined: 31 Dec 1969
Location: Russian Federation
Concentration: Entrepreneurship, International Business
WE: Supply Chain Management (Energy and Utilities)

Re: What is the value of a?
[#permalink]
Show Tags
01 Sep 2010, 07:28
This question has issues, so don't spend too much time thinking about it. Zero is neither positive nor negative. I seriously doubt you would see a question on the real GMAT about positive zero vs. negative zero. GMAT tends to avoid topics that are ambiguous.



Math Expert
Joined: 02 Sep 2009
Posts: 54440

Re: What is the value of a?
[#permalink]
Show Tags
01 Sep 2010, 07:40
HustleHarder wrote: What is the value of a? 1. a  b + 4 = 0 2. a = a Since "a" = a, 2a = 0, or a = 0 Am I missing something here? How does 2a = 0? Confused about this one, given that a is an unknown variable. Thanks What is the value of a? (1) a  b + 4 = 0 > two variables, one equation, so we can not find uniques numerical value of \(a\). Not sufficient. (2) a = a > number equals to minus itself, only number to satisfy this is zero, so \(a=0\). Sufficient. Or: \(a=a\) > add \(a\) to both sides: \(a+a=a+a\) > \(2a=0\) > \(a=0\). Answer: B. HustleHarder wrote: Source is the ARCO GMAT/GRE book. I don't understand how a = 0 To me (intuitively) if a is positive, a is negative, and if a is negative, a is positive. Hrumphhhh! You are right "if a is positive, a is negative, and if a is negative, a is positive". But also if \(a=0\), then \(a=a=0\) (0=0).
_________________



Manager
Joined: 06 Jul 2014
Posts: 94
Location: India
Concentration: Finance, Entrepreneurship

Re: What is the value of a?
[#permalink]
Show Tags
14 Aug 2017, 06:46
1st statement is definitely not sufficient. 2nd statement is sufficient if you add a to both sides. 2a=0 => a=0



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 5807
Location: United States (CA)

Re: What is the value of a?
[#permalink]
Show Tags
24 Aug 2017, 13:38
HustleHarder wrote: What is the value of a?
(1) a  b + 4 = 0 (2) a = a a  b + 4 = 0 This means a = b  4. However, since we don’t know anything about b, statement one alone is not sufficient to determine the value of a. Statement Two Alone: a = a a = a 2a = 0 a = 0 Statement two alone is sufficient to answer the question. Answer: B
_________________
5star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews




Re: What is the value of a?
[#permalink]
24 Aug 2017, 13:38






