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

It is currently 22 Aug 2014, 04:29

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

DS - odd/even problem (m04q06)

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
1 KUDOS received
Manager
Manager
User avatar
Joined: 02 Aug 2007
Posts: 146
Followers: 1

Kudos [?]: 10 [1] , given: 0

DS - odd/even problem (m04q06) [#permalink] New post 16 Nov 2007, 17:10
1
This post received
KUDOS
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

73% (01:38) correct 27% (00:23) wrong based on 230 sessions
Is integer R even?

1. R^3 + R^2 is even
2. 3R is divisible by 6

[Reveal] Spoiler: OA
B

Source: GMAT Club Tests - hardest GMAT questions
[Reveal] Spoiler: OA
Kaplan Promo CodeKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Manager
Manager
User avatar
Joined: 02 Aug 2007
Posts: 146
Followers: 1

Kudos [?]: 10 [0], given: 0

 [#permalink] New post 16 Nov 2007, 17:20
1) INSUFF
odd^2 or odd^3 = odd
even^2 or even^3 = even
So could be either even or odd.

2) SUFFICIENT B.
If 3R is divisible by 6, then 3R contains a prime number 2. An even* anything is even. This is sufficient.
CEO
CEO
User avatar
Joined: 29 Mar 2007
Posts: 2593
Followers: 16

Kudos [?]: 183 [0], given: 0

GMAT Tests User
Re: DS - odd/even problem [#permalink] New post 16 Nov 2007, 23:05
yuefei wrote:
Is integer R even?

1) R3 + R2 is even
2) 3R is divisible by 6


Im kinda confused about s1 is it 3R +2R??? or is it R^3 +R^2???

If so I get it as suff. Remember R is an integer as stated by the original stem.

1: 3R+2R. 2R will always be even. 3R can be odd or even. However,
we have O+E=E... not true. So 3R must also be even. E+E=E... true.

so R must be even or 3R will not be even.

2: obviously sufficient.


1: again. R^3+R^2 =E R can be both E or O.

E+E=E O+O=E insuff.


So its either D or B.
SVP
SVP
User avatar
Joined: 05 Jul 2006
Posts: 1542
Followers: 5

Kudos [?]: 67 [0], given: 39

 [#permalink] New post 16 Nov 2007, 23:48
Is integer R even?

1) R3 + R2 is even
2) 3R is divisible by 6

from one

r^2(r+1) = even , odd* even = even, even*even = even

insuff

from 2

suff

answer is B
Manager
Manager
User avatar
Joined: 02 Aug 2007
Posts: 146
Followers: 1

Kudos [?]: 10 [0], given: 0

 [#permalink] New post 17 Nov 2007, 17:05
Sorry, to clarify:
1) should be R^2 + R^3

This is insufficient. If R is odd, then R^2 and R^3 will also be odd. Same goes if R is even.

OA B
Intern
Intern
avatar
Joined: 19 Nov 2007
Posts: 4
Followers: 0

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

Re: DS - odd/even problem [#permalink] New post 20 Nov 2007, 00:59
yuefei wrote:
Is integer R even?

1) R3 + R2 is even
2) 3R is divisible by 6


Since (R3+R2) is even(It is given in first condition)
now R2 is always is even(R*2)
for (R3+R2) to be Even, R3 must be even bcos only even + even = Even.
for this R must be even bcos EvenR * 3 = even.
therefore condition one alone is sufficient.
now from i condition 2 it is clear the R is even.
therfore 2 alone itself is sufficient.


Therfore Ans must be D
2 KUDOS received
Intern
Intern
avatar
Joined: 25 Aug 2010
Posts: 44
Followers: 1

Kudos [?]: 12 [2] , given: 3

Re: DS - odd/even problem (m04q06) [#permalink] New post 10 Nov 2010, 06:44
2
This post received
KUDOS
yuefei wrote:
Is integer R even?

1. R^3 + R^2 is even
2. 3R is divisible by 6

[Reveal] Spoiler: OA
B

Source: GMAT Club Tests - hardest GMAT questions

my way proposed as follows.

1. R^3+R^2=R^2(R+1)
in R*R*(R+1), there is at least one number even, so we don't know if R is odd or even when the result is even.

2. \frac{3R}{6}=\frac{3R}{2*3}=\frac{R}{2}
since \frac{R}{2} is an integer (divisible by 6), R should be even.

thus B.
Intern
Intern
avatar
Joined: 28 Sep 2010
Posts: 1
Followers: 0

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

Re: DS - odd/even problem (m04q06) [#permalink] New post 10 Nov 2010, 08:03
In statement #2, what would happen if zero is considered? Zero is an integer, however it is neither odd nor even. Am I thinking too much for the purpose of GMAT?

Also if I encounter this question on GMAT exam, should I consider zero at all? :roll:

Thanks
Manager
Manager
avatar
Joined: 16 Feb 2010
Posts: 226
Followers: 2

Kudos [?]: 61 [0], given: 16

GMAT Tests User
Re: DS - odd/even problem (m04q06) [#permalink] New post 10 Nov 2010, 20:33
peterwang wrote:
In statement #2, what would happen if zero is considered? Zero is an integer, however it is neither odd nor even. Am I thinking too much for the purpose of GMAT?

Also if I encounter this question on GMAT exam, should I consider zero at all? :roll:

Thanks


zero is a non-negative and non-positive EVEN number for GMAT....
Intern
Intern
User avatar
Joined: 25 Nov 2009
Posts: 46
Location: India
Followers: 3

Kudos [?]: 4 [0], given: 8

Re: DS - odd/even problem (m04q06) [#permalink] New post 11 Nov 2010, 08:36
To check 1 apply basic rules:

Odd + Odd = Even
Even + Even = Even

and Odd/Even raise to anything remains Odd/Even.
Thus 1 takes us no where.

To check 2 :

6 = 2*3
Thus if 3R is divisible by 6, 2 is a factor of R and thus R is even.
_________________

When going gets tough, tough gets going.........

Manager
Manager
User avatar
Status: I rest, I rust.
Joined: 04 Oct 2010
Posts: 121
Schools: ISB - Co 2013
WE 1: IT Professional since 2006
Followers: 15

Kudos [?]: 101 [0], given: 8

GMAT Tests User
Re: DS - odd/even problem (m04q06) [#permalink] New post 12 Nov 2010, 23:48
yuefei wrote:
Is integer R even?

1. R^3 + R^2 is even
2. 3R is divisible by 6

[Reveal] Spoiler: OA
B

Source: GMAT Club Tests - hardest GMAT questions


Stmnt 1: Holds true for both R=1 (odd) and R=2 (even). Insufficient.
Stmnt 2: R must be a multiple of 2 in order for 3R to be divisible 6. Sufficient.

B: 2 alone is sufficient.
_________________

Respect,
Vaibhav

PS: Correct me if I am wrong.

Current Student
User avatar
Affiliations: NABE
Joined: 25 Apr 2010
Posts: 66
Location: United States
Concentration: Strategy
GPA: 3.1
WE: Marketing (Energy and Utilities)
Followers: 1

Kudos [?]: 15 [0], given: 8

Re: DS - odd/even problem (m04q06) [#permalink] New post 14 Nov 2011, 06:34
What the...?

This is what I got in my email today as a question:

Is integer R even?

1. R^3+R^2 is even
2. 2S is divisible by 6

I was thinking what does 2S have to do with anything!? :shock:
Intern
Intern
avatar
Status: Stay Hungry, Stay Foolish.
Joined: 05 Sep 2011
Posts: 41
Location: India
Concentration: Marketing, Social Entrepreneurship
GMAT 1: 650 Q V
Followers: 0

Kudos [?]: 7 [0], given: 6

Re: DS - odd/even problem (m04q06) [#permalink] New post 14 Nov 2011, 07:19
Statement 1)
R^2 (1 + R) is Even.

This can be Even*Even OR Odd*Even, which results in an Even number.
Hence insufficient.

Statement 2)
3R/ 6 is even.
3R will be multiple of 6.
R will take all those values that are even,and when multiplied by 3 will give a multiple of 6.
Therefore, R is even.
Sufficient.

Hence, B.
Manager
Manager
avatar
Joined: 21 Nov 2010
Posts: 133
Followers: 0

Kudos [?]: 5 [0], given: 12

Re: DS - odd/even problem (m04q06) [#permalink] New post 16 Nov 2011, 17:08
B.

I got this as a question of the day and 2 was written as 2s is divisible by 6 and I was thinking this problem seems way too easy...makes sense now.
Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 19047
Followers: 3367

Kudos [?]: 24498 [1] , given: 2680

Re: DS - odd/even problem (m04q06) [#permalink] New post 14 Nov 2012, 05:57
1
This post received
KUDOS
Expert's post
yuefei wrote:
Is integer R even?

1. R^3 + R^2 is even
2. 3R is divisible by 6

[Reveal] Spoiler: OA
B

Source: GMAT Club Tests - hardest GMAT questions


Is integer r even?

(1) r^3+r^2 is even --> both even and odd values of r satisfy this statement: odd^3+odd^2=odd+odd=even and even^3+even^2=even+even=even. Not sufficient.

(2) 3r is divisible by 6 --> \frac{3r}{6}=integer --> \frac{r}{2}=integer --> r=2*integer --> r=even. Sufficient.

Answer: B.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

UC Irvine Thread Master
User avatar
Joined: 15 Aug 2012
Posts: 98
Location: India
Concentration: Technology, Strategy
Schools: Merage '15 (A)
GPA: 3.6
WE: Consulting (Computer Software)
Followers: 1

Kudos [?]: 26 [0], given: 14

Re: DS - odd/even problem (m04q06) [#permalink] New post 14 Nov 2012, 08:08
for 1:
R = 1 => R cube + R sqr = 2 (even)
R = 2 => R cube + R sqr = 12 (even)
R = 3 => R cube + R sqr = 36 (even)
R = 4 => R cube + R sqr = 82 (even)

so we get all values(even + odd) of R for which the eqn is even. NOT SUFFICIENT

for 2:
R = 1 => 3R = 3 => is div by 6 (no)
R = 2 => 3R = 6 => is div by 6 (yes)
R = 3 => 3R = 9 => is div by 6 (no)
R = 4 => 3R = 12 => is div by 6 (yes)

thus it gives us "is div by 6 -yes" of eqn for even values of R.
Hence B is SUFFICIENT.
Senior Manager
Senior Manager
avatar
Joined: 08 Jun 2010
Posts: 397
Location: United States
Concentration: General Management, Finance
GMAT 1: 680 Q50 V32
Followers: 2

Kudos [?]: 55 [0], given: 13

GMAT Tests User
Re: DS - odd/even problem (m04q06) [#permalink] New post 15 Nov 2012, 16:53
Please correct the Arithmetic and Critical Reasoning question as of 14th Nov 2012.

Answer B is not phrased correctly.

The variable s is not mentioned in the question stem and hence cannot be the answer. The variable s should be variable R.
Re: DS - odd/even problem (m04q06)   [#permalink] 15 Nov 2012, 16:53
    Similar topics Author Replies Last post
Similar
Topics:
DS problem suhasrao 1 19 Jan 2010, 18:01
Experts publish their posts in the topic GMAT Prep Odd/Even Problem JimmyWorld 2 21 Dec 2009, 11:19
4 Experts publish their posts in the topic DS - odd/even problem (m04q06) yuefei 16 16 Nov 2007, 17:10
1 Odd/Even vksunder 11 03 Oct 2008, 09:54
DS problem ... help! likar 0 22 Feb 2006, 10:13
Display posts from previous: Sort by

DS - odd/even problem (m04q06)

  Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: Bunuel, WoundedTiger



cron

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®.