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

It is currently 30 May 2016, 09:52
GMAT Club Tests

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

For a set X containing n integers, is the mean even? (1) n

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

Hide Tags

2 KUDOS received
Manager
Manager
avatar
Joined: 26 Mar 2007
Posts: 87
Concentration: General Management, Leadership
Schools: Thunderbird '15
Followers: 1

Kudos [?]: 110 [2] , given: 8

For a set X containing n integers, is the mean even? (1) n [#permalink]

Show Tags

New post 09 Mar 2011, 10:15
2
This post received
KUDOS
9
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  75% (hard)

Question Stats:

45% (02:02) correct 55% (00:47) wrong based on 260 sessions

HideShow timer Statistics

For a set X containing n integers, is the mean even?

(1) n is even.

(2) All of the integers in set X are even.

Best approach :wink:
[Reveal] Spoiler: OA
Director
Director
avatar
Status: Impossible is not a fact. It's an opinion. It's a dare. Impossible is nothing.
Affiliations: University of Chicago Booth School of Business
Joined: 03 Feb 2011
Posts: 920
Followers: 13

Kudos [?]: 294 [0], given: 123

Reviews Badge
Re: Even Mean [#permalink]

Show Tags

New post 09 Mar 2011, 10:31
This one is tricky.

1. Insufficient
n = 2
X = {0,2} mean = 1. The answer is NO
X = {3,5} mean = 4. The answer is YES

2. Insufficient
X = {0,2} mean = 1. The answer is NO
X = {2,2} mean = 2. The answer is YES

1) + 2)
X = {0,2} mean = 1. The answer is NO
X = {2,2} mean = 2. The answer is YES

Hence E.

kannn wrote:
For a set X containing n integers, is the mean even?

(1) n is even.

(2) All of the integers in set X are even.

Best approach :wink:

Last edited by gmat1220 on 09 Mar 2011, 10:32, edited 1 time in total.
Expert Post
2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 33063
Followers: 5776

Kudos [?]: 70904 [2] , given: 9857

For a set X containing n integers, is the mean even? (1) n [#permalink]

Show Tags

New post 09 Mar 2011, 10:32
2
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
kannn wrote:
For a set X containing n integers, is the mean even?

(1) n is even.

(2) All of the integers in set X are even.

Best approach :wink:


For a set X containing n integers, is the mean even?

The mean of a set = The sum of the elements / number of elements, so the question is whether mean=sum/n=even.

(1) n is even --> mean=sum/even. Not sufficient.

(2) All of the integers in set X are even --> so the sum of the elements is even --> mean=even/n. Not sufficient.

(1)+(2) The question becomes whether mean=even/even=even, which can not be determined as even/even could be even (for example 4/2=2=even), could be odd (for example 6/2=3=odd) or could be non-integer (for example 6/4=3/2). Not sufficient.

Answer: E.
_________________

New to the Math Forum?
Please read this: 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

SVP
SVP
avatar
Joined: 16 Nov 2010
Posts: 1673
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 34

Kudos [?]: 442 [0], given: 36

Premium Member Reviews Badge
Re: Even Mean [#permalink]

Show Tags

New post 09 Mar 2011, 21:55
From (1), 1,2 mean = 1.5 or 4,8 mean = 6, so (1) is not enough


Again, 2,4 mean = 3 or 4,8 mean = 6, so (2) is not enough

From (1) and (2), there is no definitive conclusion, so answer is E.
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Director
Director
User avatar
Status: Tutor - BrushMyQuant
Joined: 05 Apr 2011
Posts: 557
Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 570 Q49 V19
GMAT 2: 700 Q51 V31
GPA: 3
WE: Information Technology (Computer Software)
Followers: 86

Kudos [?]: 457 [0], given: 53

Re: For a set X containing n integers, is the mean even? [#permalink]

Show Tags

New post 10 Sep 2012, 06:05
For a set X containing n integers, is the mean even?

(1) n is even.

(2) All of the integers in set X are even.

Doesn't both the statements combined give an odd answer? Thus Statement (C) is correct but the MGMAT says that (E) is correct. Can someone explain the answer.

take Set S as {2,4} then you will get the mean as 3 (odd)
take Set S as {4,4,4,4} then you will get the mean as 4 (even)

so answer will be E
_________________

Ankit

Check my Tutoring Site -> Brush My Quant

GMAT Quant Tutor
How to start GMAT preparations?
How to Improve Quant Score?
Gmatclub Topic Tags
Check out my GMAT debrief

How to Solve :
Statistics || Reflection of a line || Remainder Problems || Inequalities

Intern
Intern
User avatar
Joined: 17 Mar 2011
Posts: 11
Schools: INSEAD, Booth, LBS
WE 1: Operations,
WE 2: IT Consulting, Hi Tech Project Management
WE 3: Baby Sitter
Followers: 0

Kudos [?]: 5 [0], given: 13

GMAT ToolKit User
Re: For a set X containing n integers, is the mean even? [#permalink]

Show Tags

New post 09 May 2014, 10:40
Trick here is that integers in Set S is NOT UNIQUE EVEN INTEGER. Hence Ans. E. If integers were unique EVEN integers then Ans. would have been C.
_________________

The question isn’t who is going to let me; it’s who is going to stop me.

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 9703
Followers: 467

Kudos [?]: 120 [0], given: 0

Premium Member
Re: For a set X containing n integers, is the mean even? (1) n [#permalink]

Show Tags

New post 24 Jun 2014, 11:33
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

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 9703
Followers: 467

Kudos [?]: 120 [0], given: 0

Premium Member
Re: For a set X containing n integers, is the mean even? (1) n [#permalink]

Show Tags

New post 28 Aug 2015, 23:18
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

Senior Manager
Senior Manager
avatar
Joined: 15 Sep 2011
Posts: 331
Location: United States
WE: Corporate Finance (Manufacturing)
Followers: 6

Kudos [?]: 248 [0], given: 44

GMAT ToolKit User
For a set X containing n integers, is the mean even? (1) n [#permalink]

Show Tags

New post 16 Sep 2015, 19:21
asif780 wrote:
Trick here is that integers in Set S is NOT UNIQUE EVEN INTEGER. Hence Ans. E. If integers were unique EVEN integers then Ans. would have been C.


Not true, for instance.

If set {2,4}, then Avg. = 3
If set {2,6}, then Avg. = 4

Since both sets are unique even integers, the average can still be odd of even, and therefore whatever is above is not valid.
Intern
Intern
avatar
Joined: 05 Nov 2012
Posts: 33
Followers: 0

Kudos [?]: 4 [0], given: 13

Reviews Badge
Re: For a set X containing n integers, is the mean even? (1) n [#permalink]

Show Tags

New post 03 Feb 2016, 02:34
Bunuel wrote:
kannn wrote:
For a set X containing n integers, is the mean even?

(1) n is even.

(2) All of the integers in set X are even.

Best approach :wink:


For a set X containing n integers, is the mean even?

The mean of a set = The sum of the elements / number of elements, so the question is whether mean=sum/n=even.

(1) n is even --> mean=sum/even. Not sufficient.

(2) All of the integers in set X are even --> so the sum of the elements is even --> mean=even/n. Not sufficient.

(1)+(2) The question becomes whether mean=even/even=even, which can not be determined as even/even could be even (for example 4/2=2=even), could be odd (for example 6/2=3=odd) or could be non-integer (for example 6/4=3/2). Not sufficient.

Answer: E.


Hi Bunuel,

I still do not understand how to solve these kind of questions methodically because everytime we have to consider cases I forget one or other cases to consider. So instead of trying numbers can you please describe a methodical approach to test this.

For eg when we consider cases how many cases are possible and how to check against them. Such as we know that for the mean to be even the sum mandatorily has to be even however the base could be even or odd and can yield even or odd mean in both the cases i.e when N= even or when n=odd as non integers are also included.
Re: For a set X containing n integers, is the mean even? (1) n   [#permalink] 03 Feb 2016, 02:34
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic The set S contains n integers. Is the sum of all the elements of set S Bunuel 3 20 Dec 2015, 05:35
Experts publish their posts in the topic If n is an integer, is n - 1 even? Bunuel 4 06 Dec 2015, 12:09
Experts publish their posts in the topic If n is an integer, is n even? NoHalfMeasures 5 10 Aug 2014, 12:22
8 Experts publish their posts in the topic If n is an integer, is n even? Bunuel 11 26 Aug 2012, 03:12
Experts publish their posts in the topic Is integer N even? 1) N^2=N 2)N=N^3 Statement (1) ALONE is Lombards 3 17 Feb 2011, 14:33
Display posts from previous: Sort by

For a set X containing n integers, is the mean even? (1) n

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


GMAT Club MBA Forum Home| About| 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®.