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

It is currently 25 Oct 2014, 02:45

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

Is the integer n odd?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 06 Jul 2010
Posts: 75
Followers: 1

Kudos [?]: 38 [0], given: 12

Is the integer n odd? [#permalink] New post 01 Jun 2011, 14:43
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

58% (02:09) correct 42% (01:12) wrong based on 78 sessions
Is the integer n odd?

(1) n^2-2n is not a multiple of 4
(2) n is a multiple of 3

[Reveal] Spoiler:
They say that n(n-2) becomes divisible by 4 as soon as n is even, so n must be odd.
Well what about n=2? -->Isn't n^2-2n=0, an even integer? Did Manhattan Gmat forget about that option?
[Reveal] Spoiler: OA

Last edited by heyholetsgo on 02 Jun 2011, 03:16, edited 2 times in total.
Manhattan GMAT Discount CodesKaplan GMAT Prep Discount CodesVeritas Prep GMAT Discount Codes
Math Forum Moderator
avatar
Joined: 20 Dec 2010
Posts: 2037
Followers: 128

Kudos [?]: 956 [0], given: 376

Re: What about 0? [#permalink] New post 01 Jun 2011, 14:52
heyholetsgo wrote:
Is the integer n odd?

1.) n^2-2n
2.) n is a multiple of 3
[Reveal] Spoiler:
Well what about n=2? --> n^2-2n=0, an even integer? Did Manhattan Gmat forget about that option?


Guess you missed the RHS in statement 1:

1.) n^2-2n=0

n^2-2n=0
n(n-2)=0

Thus,
Either n=2 or n=0. Both are even.

We can conclusively say that "No, n is not odd"
Sufficient.

2)
n can be 3
OR
n can be 6.
Not Sufficient.

Ans: "A"
_________________

~fluke

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Director
Director
avatar
Joined: 01 Feb 2011
Posts: 768
Followers: 14

Kudos [?]: 58 [0], given: 42

CAT Tests
Re: What about 0? [#permalink] New post 01 Jun 2011, 15:52
1. Sufficient

n^2-2n =0

=> n=0 or n =2

in both the situations n is not odd and enough to answer the question

2. Not sufficient

as n can be 0 or 3 or 6 or 9....

Answer is A.
Manager
Manager
avatar
Joined: 05 Jul 2010
Posts: 205
Followers: 1

Kudos [?]: 11 [0], given: 18

Re: What about 0? [#permalink] New post 01 Jun 2011, 18:13
Yes, Clear A. B can be odd and even.
Manager
Manager
avatar
Joined: 06 Jul 2010
Posts: 75
Followers: 1

Kudos [?]: 38 [0], given: 12

Re: What about 0? [#permalink] New post 02 Jun 2011, 03:15
Uhhh, I'm sorry guys, forgot a tiny but important part of the question....
[Reveal] Spoiler:
They say that n(n-2) becomes divisible by 4 as soon as n is even, so n must be odd. But I believe n could be 2 such that the result is even --> 0.
Math Forum Moderator
avatar
Joined: 20 Dec 2010
Posts: 2037
Followers: 128

Kudos [?]: 956 [0], given: 376

Re: What about 0? [#permalink] New post 02 Jun 2011, 03:37
heyholetsgo wrote:
Uhhh, I'm sorry guys, forgot a tiny but important part of the question....
[Reveal] Spoiler:
They say that n(n-2) becomes divisible by 4 as soon as n is even, so n must be odd. But I believe n could be 2 such that the result is even --> 0.


Oh!!!
n^2-2n will be divisible by 4 for all even n's. But statement 1 says that the expression is not divisible by 4. Thus, "n" is definitely not even; all integers are either even or odd; if n is not even, it is odd.

Thus, the answer to the question is:
Yes, "n" is odd.
And statement 1 is sufficient.
****************************

If n=2; n(n-2)=2*0=0; "0" is divisible by 4. Thus, n=2 doesn't fit well with the condition given in statement 1.

Note:
0 is even.
0 is divisible by all real numbers but 0 itself.
0 is a multiple of all real numbers.
_________________

~fluke

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 06 Jul 2010
Posts: 75
Followers: 1

Kudos [?]: 38 [0], given: 12

Re: What about 0? [#permalink] New post 02 Jun 2011, 05:18
Damn, 0 is divisible by 4. Thanks man;)
Intern
Intern
avatar
Joined: 16 Oct 2011
Posts: 27
GMAT 1: 640 Q44 V35
GMAT 2: 720 Q47 V42
Followers: 0

Kudos [?]: 3 [0], given: 5

Re: What about 0? [#permalink] New post 19 Oct 2011, 00:35
fluke wrote:
Note:
0 is even.
0 is divisible by all real numbers but 0 itself.
0 is a multiple of all real numbers.

Is this correct? I would have thought a number is even only if it is divisible by 2 without there being any remainder.

*Edit*
I retract my question. Since even+even=even, zero must be an even number. Sorry for the confusion!
_________________

GMAT 720 Q47 V42 AWA 6.0, TOEFL 110.

Intern
Intern
avatar
Joined: 18 Mar 2011
Posts: 33
Followers: 0

Kudos [?]: 6 [0], given: 24

CAT Tests
Re: What about 0? [#permalink] New post 20 Oct 2011, 22:55
hey

but how can u equate statement 1 to zero ? Its not given rite ?

Am I missing some thing silly ?
Math Forum Moderator
avatar
Joined: 20 Dec 2010
Posts: 2037
Followers: 128

Kudos [?]: 956 [0], given: 376

Re: What about 0? [#permalink] New post 20 Oct 2011, 23:48
Priyanka2011 wrote:
hey

but how can u equate statement 1 to zero ? Its not given rite ?

Am I missing some thing silly ?


We can't equate it to 0. My first reply was to an incomplete question. My second reply was the valid one.

Please ignore:
what-about-114534.html#p928398

Valid reply:
what-about-114534.html#p928609
_________________

~fluke

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Current Student
avatar
Joined: 26 Sep 2013
Posts: 232
Concentration: Finance, Economics
GMAT 1: 670 Q39 V41
GMAT 2: 730 Q49 V41
Followers: 2

Kudos [?]: 39 [0], given: 40

Is the integer n odd? (1) n^2 – 2n is not a multiple of 4. [#permalink] New post 13 Nov 2013, 10:45
Is the integer n odd?

(1) n^2 – 2n is not a multiple of 4.
(2) n is a multiple of 3.

[Reveal] Spoiler: OE
(1) SUFFICIENT:n^2 – 2n = n(n – 2). If n is even, both terms in this product will be even, and the
product will be divisible by 4. Since n2 – 2n is not a multiple of 4, we know that the integer n
cannot be even—it must be odd.

(2) INSUFFICIENT: Multiples of 3 can be either odd or even.



Here's my question: With regards to (1), n could be 2, in which case 2(2-2)=0, in which case the expression is not a multiple of 4, but n is even. Thus shouldn't the answer be E?
Expert Post
Verbal Forum Moderator
Verbal Forum Moderator
User avatar
Joined: 10 Oct 2012
Posts: 628
Followers: 43

Kudos [?]: 599 [0], given: 135

Premium Member
Re: Is the integer n odd? (1) n^2 – 2n is not a multiple of 4. [#permalink] New post 13 Nov 2013, 10:51
Expert's post
AccipiterQ wrote:

Here's my question: With regards to (1), n could be 2, in which case 2(2-2)=0, in which case the expression is not a multiple of 4, but n is even. Thus shouldn't the answer be E?


0 is a multiple of every integer except zero itself.
_________________

All that is equal and not-Deep Dive In-equality

Hit and Trial for Integral Solutions

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3613

Kudos [?]: 28940 [0], given: 2871

Re: Is the integer n odd? (1) n^2 – 2n is not a multiple of 4. [#permalink] New post 13 Nov 2013, 10:53
Expert's post
AccipiterQ wrote:
Is the integer n odd?

(1) n^2 – 2n is not a multiple of 4.
(2) n is a multiple of 3.

[Reveal] Spoiler: OE
(1) SUFFICIENT:n^2 – 2n = n(n – 2). If n is even, both terms in this product will be even, and the
product will be divisible by 4. Since n2 – 2n is not a multiple of 4, we know that the integer n
cannot be even—it must be odd.

(2) INSUFFICIENT: Multiples of 3 can be either odd or even.



Here's my question: With regards to (1), n could be 2, in which case 2(2-2)=0, in which case the expression is not a multiple of 4, but n is even. Thus shouldn't the answer be E?


Merging similar topics.
_________________

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

1 KUDOS received
Manager
Manager
User avatar
Joined: 04 Oct 2013
Posts: 79
Location: United States
Concentration: Finance, Leadership
GMAT 1: 590 Q40 V30
GPA: 3.98
WE: Project Management (Entertainment and Sports)
Followers: 4

Kudos [?]: 29 [1] , given: 17

Re: Is the integer n odd? (1) n^2 – 2n is not a multiple of 4. [#permalink] New post 07 Jan 2014, 01:38
1
This post received
KUDOS
1. n^2-2n is not a multiple of 4.

follows n(n-2)is not a multiple of 4

find out in which points the equation yields zero, zero is a multiple of 4 as well as a multiple of any number except zero itself.
value a=0 and value b=2 thus n must not be any of those two values because otherwise the expression would result in a multiple of 4
-n can be both positive or negative, the only restriction is that n is an integer- since o and 2 are out of the pool 4 would be the first positive even number applicable to n. Every other positive even number would cause the expression to be a multiple of 4. We can safely say that n is for sure not an even number. before submitting the answer let's quickly check how the expression behaves with negatives.

if n=-2 the greatest negative even integer plugged n^2-2n results in a multiple of 4 then for sure n is odd.

Sufficient.


2. n is a multiple of 3.
Non sufficient, n could be zero.
_________________

Either suffer the pain of discipline, or suffer the pain of regret.

If my posts are helping you show some love awarding a kudos

Manager
Manager
avatar
Joined: 21 Oct 2013
Posts: 186
Location: Germany
Concentration: Accounting, International Business
GMAT 1: 660 Q45 V36
GPA: 3.91
Followers: 0

Kudos [?]: 16 [0], given: 19

Re: Is the integer n odd? [#permalink] New post 23 Jan 2014, 23:39
(1) n²-2n ==> n(n-2) = 0. Thus, n = 2 or n = 0. Both are multiples of 4. Every other even integer (also the negatives) result in a multiple of 4. Thus n is clearly odd.
You could also just plug in numbers....

(2) n is a multiple of 3 --> clearly IS. could be 6 or 9 or 12 or 15 and so on.
Re: Is the integer n odd?   [#permalink] 23 Jan 2014, 23:39
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic If n is a positive integer, is n odd? Bunuel 1 14 Jul 2014, 02:38
Experts publish their posts in the topic If n is an integer, is n + 1 odd? Bunuel 4 30 Jul 2012, 01:15
1 Experts publish their posts in the topic Is the positive integer n an odd integer? Stiv 2 01 May 2012, 00:13
4 Experts publish their posts in the topic Is the integer n odd? Nihit 10 15 Nov 2008, 08:44
Is the integer n odd? karovd 4 30 Oct 2004, 10:37
Display posts from previous: Sort by

Is the integer n odd?

  Question banks Downloads My Bookmarks Reviews Important topics  


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®.