Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 25 May 2017, 04:47

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# The mean of four integers will not change if all the

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
SVP
Joined: 04 May 2006
Posts: 1902
Schools: CBS, Kellogg
Followers: 23

Kudos [?]: 1122 [0], given: 1

The mean of four integers will not change if all the [#permalink]

### Show Tags

14 May 2008, 03:13
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

The mean of four integers will not change if all the integers are multiplied by any constant. What is always true about this set of numbers?

I. The mean of the set is 0

II. The sum of the largest member and the smallest member of the set is 0

III. The set contains both positive and negative integers

I only
II only
III only
I and II only
I, II, and III
_________________
CEO
Joined: 17 Nov 2007
Posts: 3586
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 574

Kudos [?]: 3976 [0], given: 360

### Show Tags

14 May 2008, 04:15
I guess I and III, but this onption is not included here.

I. if we write out the formula of mean, we can easily find that mean has to be 0

II. {-3,-1, 0,4} satisfies the condition, but the sum of the largest member and the smallest member of the set is 4-3=1

III. A set of something means in GMAT non repetitive list. So, the set has to contain positive and negative integers to have the mean=0. {0,0,0,0} - is not a set in GMAT.
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Current Student
Joined: 28 Dec 2004
Posts: 3363
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 15

Kudos [?]: 297 [0], given: 2

### Show Tags

14 May 2008, 05:09
i think its 1 only..

we could have all 0s in the set as well..

{0,0,0} where the mean=0

sum of largest+smallest=0..

and it doesnt have to have negative or positive integers..
CEO
Joined: 17 Nov 2007
Posts: 3586
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Followers: 574

Kudos [?]: 3976 [0], given: 360

### Show Tags

14 May 2008, 06:26
the question about set is still open for me (look at 7-t61572)

I have not seen so far at least one real GMAT problem that tests the set concept. So, I think that problems like this one do not reflect real GMAT.
_________________

HOT! GMAT TOOLKIT 2 (iOS) / GMAT TOOLKIT (Android) - The OFFICIAL GMAT CLUB PREP APP, a must-have app especially if you aim at 700+ | PrepGame

Current Student
Joined: 28 Dec 2004
Posts: 3363
Location: New York City
Schools: Wharton'11 HBS'12
Followers: 15

Kudos [?]: 297 [0], given: 2

### Show Tags

14 May 2008, 07:06
walker wrote:
the question about set is still open for me (look at 7-t61572)

I have not seen so far at least one real GMAT problem that tests the set concept. So, I think that problems like this one do not reflect real GMAT.

i remember having this issue at college in Computer sci..sets contain unique different integers..however mathematically a set can have repeating numbers..i believe OG prefers the mathematical definition
SVP
Joined: 04 May 2006
Posts: 1902
Schools: CBS, Kellogg
Followers: 23

Kudos [?]: 1122 [0], given: 1

### Show Tags

15 May 2008, 21:10
Thanks Walker and fresinha12. Your reasoning really helps me out on this, and ofcourse be better than OE.

OA is A
_________________
Re: M12-30   [#permalink] 15 May 2008, 21:10
Display posts from previous: Sort by

# The mean of four integers will not change if all the

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 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®.