Inequality - Sum of numbers : GMAT Problem Solving (PS)
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 04 Dec 2016, 17:58

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

Inequality - Sum of numbers

Author Message
TAGS:

Hide Tags

Manager
Joined: 06 Apr 2010
Posts: 143
Followers: 3

Kudos [?]: 636 [0], given: 15

Inequality - Sum of numbers [#permalink]

Show Tags

27 Aug 2010, 22:09
00:00

Difficulty:

(N/A)

Question Stats:

50% (00:00) correct 50% (00:00) wrong based on 2 sessions

HideShow timer Statistics

The sum of all the integers k such that –26 < k < 24 is
A. 0
B. -2
C. -25
D. -49
E. -51

What is the trap here...I am getting answer as -51 where as OA is diff.
[Reveal] Spoiler: OA
Manager
Joined: 09 Jun 2010
Posts: 116
Followers: 2

Kudos [?]: 111 [0], given: 1

Re: Inequality - Sum of numbers [#permalink]

Show Tags

28 Aug 2010, 06:11
-25------------------0-----------------23

values upto + 23 cancels out & we are left with only -25 & -24 sum of which is - 49. hence option D.

Since this is in equality we dont consider -26 and 24 as values of K. K is greater than -26 & less than +24 therefore range of K is -25 to 23. You might be considering -26 & 24, in that case the range becomes -26 to +24 and the answer will be 51 which is wrong.
Math Expert
Joined: 02 Sep 2009
Posts: 35843
Followers: 6837

Kudos [?]: 89859 [0], given: 10381

Re: Inequality - Sum of numbers [#permalink]

Show Tags

28 Aug 2010, 06:21
udaymathapati wrote:
The sum of all the integers k such that –26 < k < 24 is
A. 0
B. -2
C. -25
D. -49
E. -51

What is the trap here...I am getting answer as -51 where as OA is diff.

Note that the range is not inclusive: k can not be -26 or 24! That's why you are getting -51.

The sum will be: (-25)+(-24)+(-23)+...+(-1)+0+1+..+23 --> the sum of pairs -23 and 23, -22 and 22 and so on is 0 and we are left only with -25+(-24)=-49.

Or: as we have evenly spaced set: the sum will be average of the first and the last terms multiplied be the # of terms: $$\frac{-25+23}{2}*49=-49$$.

Hope it's clear.
_________________
Re: Inequality - Sum of numbers   [#permalink] 28 Aug 2010, 06:21
Similar topics Replies Last post
Similar
Topics:
3 The sum of the digits of a two digit number.. 5 14 Nov 2012, 07:34
132 The sum of four consecutive odd numbers is equal to the sum 23 21 Sep 2011, 10:52
1 Sum of Numbers 6 05 Jul 2011, 09:45
Inequality 5 21 Nov 2010, 09:20
7 Tough and tricky: The sum of the even numbers. 7 11 Oct 2009, 16:11
Display posts from previous: Sort by

Inequality - Sum of numbers

 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®.