Oct 18 08:00 AM PDT  09:00 AM PDT Learn an intuitive, systematic approach that will maximize your success on Fillintheblank GMAT CR Questions. Oct 19 07:00 AM PDT  09:00 AM PDT Does GMAT RC seem like an uphill battle? eGMAT is conducting a free webinar to help you learn reading strategies that can enable you to solve 700+ level RC questions with at least 90% accuracy in less than 10 days. Sat., Oct 19th at 7 am PDT Oct 20 07:00 AM PDT  09:00 AM PDT Get personalized insights on how to achieve your Target Quant Score. Oct 22 08:00 PM PDT  09:00 PM PDT On Demand for $79. For a score of 4951 (from current actual score of 40+) AllInOne Standard & 700+ Level Questions (150 questions) Oct 23 08:00 AM PDT  09:00 AM PDT Join an exclusive interview with the people behind the test. If you're taking the GMAT, this is a webinar you cannot afford to miss!
Author 
Message 
TAGS:

Hide Tags

Senior Manager
Affiliations: SPG
Joined: 15 Nov 2006
Posts: 273

Is A + B + C even?
[#permalink]
Show Tags
23 May 2010, 21:31
Question Stats:
19% (02:01) correct 81% (02:14) wrong based on 621 sessions
HideShow timer Statistics
Is A + B + C even? (1) A  C  B is even (2) (A  C)/B is odd
Official Answer and Stats are available only to registered users. Register/ Login.




Math Expert
Joined: 02 Sep 2009
Posts: 58409

Re: Is A + B + C even? (1) A  C  B is even (2) (A  C)/B is
[#permalink]
Show Tags
08 Apr 2012, 09:30
catty2004 wrote: Is A + B + C even?
(1) A  C  B is even
(2) (A  C)/B is odd Notice that we are not told that a, b and c are integers. Q: is \(a+b+c=even\)? (1) \(acb=even\), if the variables are integers then \(a+b+c\) will be even but if they are not, for example if \(a=3.5\), \(b=1\), \(c=0.5\) then \(acb=2=even\), but \(a+b+c=5=odd\). Not sufficient. (2) \(\frac{ac}{b}=odd\). The same here: if the variables are integers then \(a+b+c\) will be even but if they are not for example if \(a=3.5\), \(b=1\), \(c=0.5\) then \(\frac{ac}{b}=3=odd\), but \(a+b+c=5=odd\). Not sufficient (1)+(2) \(a+b+c\) may or may not be even (again if variables are integers: YES but if \(a=3.5\), \(b=1\), \(c=0.5\) answer is NO). Not sufficient. Answer: E.
_________________




Intern
Joined: 30 May 2008
Posts: 48

Is A + B + C even?
[#permalink]
Show Tags
Updated on: 29 Jul 2012, 07:01
Is A + B + C even?
(1) A  C  B is even
(2) (A  C)/B is odd
Originally posted by catty2004 on 08 Apr 2012, 08:17.
Last edited by Bunuel on 29 Jul 2012, 07:01, edited 2 times in total.
Edited the question




Math Expert
Joined: 02 Sep 2009
Posts: 58409

Is A + B + C even?
[#permalink]
Show Tags
24 May 2010, 02:09
Is A + B + C even?Note that we are not told that a, b and c are integers. (1) \(acb=even\), if the variables are integers then \(a+b+c\) will be even but if they are not: \(a=3.5\), \(b=1\), \(c=0.5\) > \(acb=2=even\), but \(a+b+c=5=odd\). Not sufficient. (2) \(\frac{ac}{b}=odd\). The same here: if the variables are integers then \(a+b+c\) will be even but if they are not: \(a=3.5\), \(b=1\), \(c=0.5\) > \(\frac{ac}{b}=3=odd\), but \(a+b+c=5=odd\). Not sufficient (1)+(2) \(a+b+c\) may or may not be even (again if variables are integers: YES but if \(a=3.5\), \(b=1\), \(c=0.5\) answer is NO). Not sufficient. Answer: E.
_________________



Manager
Joined: 14 Mar 2011
Posts: 184

Re: Even/Odd
[#permalink]
Show Tags
17 Sep 2011, 15:22
statement 1 ) A  c b is even
let A = 10.5, B =2 and c =4.5
10.5  4.5 2 = 4 =even, but A+B+C = 17 (NOT EVEN.)
Pick A,B,C AS 2 THEN A B C = 2 = even , A+B+C =6 (EVEN )
STATEMENT 1 INSUFFICIENT.
Statement 2 ) (AC)/b = odd
again, let A = 10.5, B =2 and c =4.5
(10.54.5)/2 = 3 =ODD, AND A+B+C = 17 = ODD
BUT Let A= 8, B= 2 And C =2
> (AC)/B = 3 = ODD, BUT A + B +C = 12 = EVEN
STATEMENT 2 INSUFFICIENT.
the same values as i have listed above will also prove combining both statements dont provide any definitive answer either.
Answer E



Manager
Joined: 12 Oct 2011
Posts: 154

Re: Is A+B+C even? 1) ACB is even 2) (AC)/B is odd
[#permalink]
Show Tags
16 Dec 2011, 22:49
E it is. I tried to solve algebraically. However, I have a question. If it were mentioned that all three numbers were integers, how would the answer change? How to figure this out algebraically? (Without having to pick numbers)
_________________
Consider KUDOS if you feel the effort's worth it



Director
Joined: 07 Aug 2011
Posts: 502
Concentration: International Business, Technology

Re: Is A+B+C even? 1) ACB is even 2) (AC)/B is odd
[#permalink]
Show Tags
17 Dec 2011, 12:13
i dont an algebric way to do it but here is a simple permutation on A,B,C "if given is that A, B , C are integers" .
then option 1 ABC is even only in below cases ACB EEE EOO (E=Even, O=Odd) OOE OEO in all cases A+ B +c will be even .
stmt 2: AB/C is odd
A/C  B/C should be odd. E O O E
A/C can be even in both cases E/E or E/O eg: 4/2 or 6/3. B/C can be even in both cases E/E or E/O eg: 4/2 or 6/3.
in the same way we can do for Odd case .
i.e. this stmt is insuff.



Manager
Joined: 12 Oct 2011
Posts: 106
GMAT 1: 700 Q48 V37 GMAT 2: 720 Q48 V40

Re: Odd/Even (Ultra hard) from Math Flashcard
[#permalink]
Show Tags
08 Apr 2012, 08:41
I think the OA is incorrect.
1)ABC can only be even, if either all are even or two are odd and one is even, in both cases a+b+c is even.
2) (AC)/B can be odd if all are even or if all are odd, so A+B+C is even or odd, which makes the statement insufficient.
IMO A is correct.



Intern
Joined: 10 Dec 2011
Posts: 9

Re: Is A + B + C even? (1) A  C  B is even (2) (A  C)/B is
[#permalink]
Show Tags
11 Oct 2012, 10:54
sanjoo wrote: Bunuel wrote: catty2004 wrote: Is A + B + C even?
(1) A  C  B is even
(2) (A  C)/B is odd Notice that we are not told that a, b and c are integers. Q: is \(a+b+c=even\)? (1) \(acb=even\), if the variables are integers then \(a+b+c\) will be even but if they are not, for example if \(a=3.5\), \(b=1\), \(c=0.5\) then \(acb=2=even\), but \(a+b+c=5=odd\). Not sufficient. (2) \(\frac{ac}{b}=odd\). The same here: if the variables are integers then \( a+b+c\) will be even but if they are not for example if \(a=3.5\), \(b=1\), \(c=0.5\) then \(\frac{ac}{b}=3=odd\), but \(a+b+c=5=odd\). Not sufficient (1)+(2) \(a+b+c\) may or may not be even (again if variables are integers: YES but if \(a=3.5\), \(b=1\), \(c=0.5\) answer is NO). Not sufficient. Answer: E. I was asking abt statement 2.. U said..if it were mentioned that a b and c are intergers than A+b+c=even ..and then this statement wud b sufficient.. But i got this now..i have solved this ..bt i tuk some time while proving this statemt 2 ... It goes like this: Q: Is A+B+C= EVEN S1: ABC= Even i.e. We can write ABC= 2N =>A=2N + B+C Substituting in the main equation we get 2N+2(B+C)=2[N+B+C] Now, N is an Integer, but we dont know whether, B+C= Integer or not. Hence N+B+C mayor may not be an Integer. Therefore, S1 is insufficient. Same case with Statement 2, which on simplification gives, A=(2N+1)B + C => A+B+C= 2(B+C+NB) Again same same scenario, We are not aware whether, the value in the parenthesis is an Integer or not. Hence, S2 is also Insufficient. S1 & S2 together also does not resolve the issue of whether B+C is integer or not. Hence answer is E. I hope this is clear. Thanks



Intern
Status: casado
Joined: 26 Jan 2010
Posts: 23
Location: chile

Re: Is A + B + C even?
[#permalink]
Show Tags
30 Nov 2014, 15:35
Note that we are not told that a, b and c are integers. Q: is a+b+c=even? (1) acb=even, if the variables are integers then a+b+c will be even but if they are not: a=3.5, b=1, c=0.5 —> acb=2=even, but a+b+c=5=odd. Not sufficient. (2) \fracacb=odd. The same here: if the variables are integers then a+b+c will be even but if they are not: a=3.5, b=1, c=0.5 —> \fracacb=3=odd, but a+b+c=5=odd. Not sufficient (1)+(2) a+b+c may or may not be even (again if variables are integers: YES but if a=3.5, b=1, c=0.5 answer is NO). Not sufficient. Answer: E. Course GMAT onsite in Chile Claudio Hurtado GMAT CHILE
_________________
claudio hurtado maturana Private lessons GMAT QUANT GRE QUANT SAT QUANT Classes group of 4 students GMAT QUANT GRE QUANT SAT QUANT Distance learning courses GMAT QUANT GRE QUANT SAT QUANT Website http://www.gmatchile.clEmail clasesgmatchile@gmail.com Skype: clasesgmatchile@gmail.com Address Avenida Hernando de Aguirre 128 Of 904, Tobalaba Metro Station, Santiago Chile.



Intern
Joined: 14 Apr 2015
Posts: 10
Location: Viet Nam
GPA: 3.1

Is A + B + C even?
[#permalink]
Show Tags
15 Apr 2015, 03:43
K is integer for sure.
1. A  (B+C) = 2K => A = 2K + B + C A +B + C = 2K +2B + 2C = 2(K + B + C)
If B: Integer; C = 0.5 => A + B + C = 2(K+B) + 1
2. (A  C)/B = 2k +1 => A  C = 2kB + B => A = 2kB + B + C => A + B + C = 2(kB + B + C) If B: Integer; C = 0.5
=> A + B + C = 2(kB + B) + 1
Quite tricky.



Current Student
Joined: 13 Nov 2014
Posts: 108

Re: Is A + B + C even?
[#permalink]
Show Tags
16 Apr 2015, 06:12
What a great question! I started this one writing out all the cases but then realized we don't know if a,b and c are integers. Got answer E and thought it took me at most 2.5 mins... nope just over 3:50. Although I finally got it, this question has made me realize I really need to improve my speed.
_________________
Gmat prep 1 600 Veritas 1 650 Veritas 2 680 Gmat prep 2 690 (48Q 37V) Gmat prep 5 730 (47Q 42V) Gmat prep 6 720 (48Q 41V)



CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2978
Location: India
GMAT: INSIGHT
WE: Education (Education)

Re: Is A + B + C even?
[#permalink]
Show Tags
10 Dec 2017, 00:15
catty2004 wrote: Is A + B + C even?
(1) A  C  B is even
(2) (A  C)/B is odd Please find the solution as attached. ANswer: Option E
Attachments
File comment: www.GMATinsight.com
Question.png [ 586.52 KiB  Viewed 4263 times ]
_________________
Prosper!!!GMATinsightBhoopendra Singh and Dr.Sushma Jha email: info@GMATinsight.com I Call us : +919999687183 / 9891333772 Online OneonOne Skype based classes and Classroom Coaching in South and West Delhihttp://www.GMATinsight.com/testimonials.htmlACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION



Manager
Joined: 20 Oct 2018
Posts: 67

Re: Is A + B + C even?
[#permalink]
Show Tags
27 Jun 2019, 23:05
Is this method correct? There are 3 variables A, B and C. We require 3 equations to solve this. But we are only given 2 equations. So E. Cherry on top is the fact that it is not given as A, B and C are integers. MathRevolution Bunuel



CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2978
Location: India
GMAT: INSIGHT
WE: Education (Education)

Is A + B + C even?
[#permalink]
Show Tags
28 Jun 2019, 04:17
vyascd wrote: Is this method correct?
There are 3 variables A, B and C. We require 3 equations to solve this. But we are only given 2 equations. So E. Cherry on top is the fact that it is not given as A, B and C are integers.
I call the use of such a method, a suicide attempt by a serious GMAT aspirant...1st statement alone would have been sufficient to answer this question if only the "cherryonthetop" were given. Solve DS as GMAT expects it to be solved... not as a few wizards explain it...
_________________
Prosper!!!GMATinsightBhoopendra Singh and Dr.Sushma Jha email: info@GMATinsight.com I Call us : +919999687183 / 9891333772 Online OneonOne Skype based classes and Classroom Coaching in South and West Delhihttp://www.GMATinsight.com/testimonials.htmlACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION



GMAT Club Legend
Joined: 18 Aug 2017
Posts: 5014
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)

Re: Is A + B + C even?
[#permalink]
Show Tags
28 Jun 2019, 10:39
dimitri92 wrote: Is A + B + C even?
(1) A  C  B is even
(2) (A  C)/B is odd given A+B+C even will be valid at o+o+e and e+e+e only #1 A  C  B is even or say A(C+B) is even if A = odd then C+B = odd ; either of c or b is even and odd and If A = even then both c & b are even so insufficient as we get ; a,b,c as ; ( o+e+o) i.e odd and (e+e+e) i.e even #2 (A  C)/B is odd a & c either is even and other is odd ; b is odd eg a=11,b=3 and c = 2 ; a+b+c ; even or a& c are even and b is odd ; eg a=8 ,c=2 and b=3 ; so a+b+c ; odd insufficient from 1& 2 we cannot determine anything in common IMO E




Re: Is A + B + C even?
[#permalink]
28 Jun 2019, 10:39






