If the sum of n consecutive integers is 0, which of the

Oldest

Best Reply

Author

Message

TAGS:

Intern

Joined: 08 Jan 2007

Posts: 42

Followers: 1

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

If the sum of n consecutive integers is 0, which of the [#permalink]

16 Jan 2007, 10:43

If the sum of n consecutive integers is 0, which of the following must be true?
I. n is an even number
II. n is an odd number
III. The average (arithmetic mean) of the n integers is 0.

A) I only
B) II only
C) III only
D) I and III
E) II and III

Intern

Joined: 15 Jan 2007

Posts: 38

Followers: 0

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

[#permalink]

16 Jan 2007, 10:54

E.
if sum is 0, average 0.
and if you take sample set, -1 0 1 .. n will always be odd.

Intern

Joined: 08 Jan 2007

Posts: 42

Followers: 1

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

[#permalink]

16 Jan 2007, 11:02

with even/odd, I thought 0 was even? how is it always odd?

SVP

Joined: 01 May 2006

Posts: 1837

Followers: 8

Kudos [?]: 73 [0], given: 0

[#permalink]

16 Jan 2007, 11:51

Agree... it is (E).

cucrose, svas was actually giving an example

This is all sarting cases of such a consecutive numbers' list:
o n=1 , List = {0}
o n=3 , List = {-1, 0, 1}
o n=5 , List = {-2, -1, 0, 1, 2}

We have to preserve the symetry : each number found in one side of 0 has its opposite number present in the other side of 0.

So:
> n is always odd (min value : n=1)
> average = sum(terms) / n = 0/n = 0

Last edited by Fig on 16 Jan 2007, 12:25, edited 1 time in total.

Intern

Joined: 08 Jan 2007

Posts: 42

Followers: 1

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

[#permalink]

16 Jan 2007, 12:12

Fig, you concluded by saying:
> n is always even (min value : n=1), do u mean odd? shouldnt min value: n=-1?

SVP

Joined: 01 May 2006

Posts: 1837

Followers: 8

Kudos [?]: 73 [0], given: 0

[#permalink]

16 Jan 2007, 12:25

cucrose wrote:

Fig, you concluded by saying:
> n is always even (min value : n=1), do u mean odd? shouldnt min value: n=-1?

Sorry.... it was of course odd

.... Edited, thanks

[#permalink] 16 Jan 2007, 12:25

		Similar topics	Author	Replies	Last post
Similar Topics:		n could be the sum of consecutive integers r, s, and t	qhoc0010	18	06 Mar 2005, 12:17
	34	The sum of n consecutive positive integers is 45	Bunuel	82	16 Oct 2009, 19:59
	10	If the sum of the consecutive integers from –42 to n	gmattokyo	16	08 Nov 2009, 03:57
	5	If the sum of n consecutive positive integers is 33, what of	aalriy	8	10 Dec 2010, 07:58
	8	The sum of n consecutive positive integers is 45. What is	neelesh	37	04 Apr 2008, 20:08

If the sum of n consecutive integers is 0, which of the

Main navigation

GMAT Resources

Partners

MBA Resources

GMAT ® is a registered trademark of the Graduate Management Admission Council ® (GMAC ®). GMAT Club's website has not been reviewed or endorsed by GMAC.

GMAT Courses

Admissions Consulting

If the sum of n consecutive integers is 0, which of the

If the sum of n consecutive integers is 0, which of the

Main navigation

GMAT Resources

Partners

MBA Resources