GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 24 Sep 2018, 18:21

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.

Close

Request Expert Reply

Confirm Cancel

Is the average (arithmetic mean) of a certain series of

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 02 Nov 2009
Posts: 17
Is the average (arithmetic mean) of a certain series of  [#permalink]

Show Tags

New post 18 Apr 2010, 13:45
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

71% (00:27) correct 29% (01:00) wrong based on 23 sessions

HideShow timer Statistics

Is the average (arithmetic mean) of a certain series of consecutive integers an integer?

(1) The number of terms in the series is even.

(2) The median of the terms in the series is not an integer.



--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.


If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
CEO
CEO
User avatar
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2617
Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Reviews Badge
Re: Math  [#permalink]

Show Tags

New post 18 Apr 2010, 13:58
1
1
IMO D

Statement 1. if number of terms is even , AM cannot be integer, hence sufficient.

take eg of 1,2,3 and 1,2,3,4

sum = n(A+L)/2 here d=1
AM = (A+L)/2 , now if A is odd , and its having even terms then L is even and vice versa .
Hence AM is not an integer.

Statement 2. if median is not an integer then , it cannot have odd number of terms, it must have even number of terms.. hence sufficient.

Thus D
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned :)

Jo Bole So Nihaal , Sat Shri Akaal

:thanks Support GMAT Club by putting a GMAT Club badge on your blog/Facebook :thanks

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Manager
Manager
avatar
Joined: 13 Dec 2009
Posts: 116
Re: Math  [#permalink]

Show Tags

New post 18 Apr 2010, 19:03
sudai wrote:
Is the average (arithmetic mean) of a certain series of consecutive integers an integer?
(1) The number of terms in the series is even.

(2) The median of the terms in the series is not an integer.


statement 1:sum of series is given by: S = n/2[2a+(n-1).d]
hence arithmetic mean A.M.= S/n => 1/2[2a+(n-1)] as d=1( consecutive integer)
=> A.M.= a+(n-1)/2
now, since n is even so n-1 is odd hence (n-1)/2 will not be integer => hence A.M. will not be an integer ....suff.

2nd statement: as gurpreetsingh has mentioned ...suff.
hence both statements are sufficient to answer.

--== Message from the GMAT Club Team ==--

THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION.
This discussion does not meet community quality standards. It has been retired.


If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8176
Premium Member
Re: Is the average (arithmetic mean) of a certain series of  [#permalink]

Show Tags

New post 05 Sep 2018, 10:11
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 Bot
Re: Is the average (arithmetic mean) of a certain series of &nbs [#permalink] 05 Sep 2018, 10:11
Display posts from previous: Sort by

Is the average (arithmetic mean) of a certain series of

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

Events & Promotions

PREV
NEXT


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.