NEW HERE? LEARN MORE
closeclose
Last visit was: 29 Apr 2024, 01:22 It is currently 29 Apr 2024, 01:22
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

How to solve this in 1,5 minute?

User avatar
PTK
VP
VP
Joined: 02 Jul 2009
Status:mission completed!
Posts: 1139
Own Kudos [?]: 2129 [0]
Given Kudos: 622
GPA: 3.77
Send PM
GMAT ToolKit User Reviews Badge
How to solve this in 1,5 minute? [#permalink] New post   03 Apr 2010, 10:57
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hide Show timer Statistics


Hi guys!

Could you please explain how to solve this problem?

What is the sum of integers presented in attached file?


(I do not know how to post a table here)

thanks.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
B
walker
SVP
SVP
Joined: 17 Nov 2007
Posts: 2408
Own Kudos [?]: 10038 [0]
Given Kudos: 361
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Send PM
GMAT ToolKit User
Re: How to solve this in 1,5 minute? [#permalink] New post   03 Apr 2010, 11:21
Expert Reply
1. Each row is n* (1+2+3...+7) where n e {1,-2,3,-4..,7}
2. Let's add all rows: Sum = (1-2+3-4+5-6+7)*(1+2+3+4+5+6+7) = 4*(3*8+4) = 4*28 = 112

EDITED: typo
User avatar
hardnstrong
Manager
Manager
Joined: 05 Mar 2010
Posts: 88
Own Kudos [?]: 91 [0]
Given Kudos: 8
Send PM
Re: How to solve this in 1,5 minute? [#permalink] New post   04 Apr 2010, 06:18
walker wrote:
1. Each row is n* (1+2+3...+7) where n e {1,-2,3,-4..,7}
2. Let's add all rows: Sum = (1-2+3-4+5-6+7)*(1+2+3+4+5+6+7) = 4*(3*8+4) = 4*28 = 108


4*28 = 112 typo?

I think this is a less than 30 sec question
User avatar
nickk
Manager
Manager
Joined: 10 Aug 2009
Posts: 81
Own Kudos [?]: 39 [0]
Given Kudos: 13
Send PM
Re: How to solve this in 1,5 minute? [#permalink] New post   04 Apr 2010, 06:22
Just a small correction walker, 4*28 = 112 ;)
User avatar
B
walker
SVP
SVP
Joined: 17 Nov 2007
Posts: 2408
Own Kudos [?]: 10038 [0]
Given Kudos: 361
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
Send PM
GMAT ToolKit User
Re: How to solve this in 1,5 minute? [#permalink] New post   04 Apr 2010, 07:13
Expert Reply
Yeah, of course it's typo. Thanks
User avatar
PTK
VP
VP
Joined: 02 Jul 2009
Status:mission completed!
Posts: 1139
Own Kudos [?]: 2129 [0]
Given Kudos: 622
GPA: 3.77
Send PM
GMAT ToolKit User Reviews Badge
Re: How to solve this in 1,5 minute? [#permalink] New post   06 Apr 2010, 11:13
walker wrote:
1. Each row is n* (1+2+3...+7) where n e {1,-2,3,-4..,7}
2. Let's add all rows: Sum = (1-2+3-4+5-6+7)*(1+2+3+4+5+6+7) = 4*(3*8+4) = 4*28 = 112

EDITED: typo



Great, thank you ! ) :roll:
User avatar
B
RaviChandra
Senior Manager
Senior Manager
Joined: 02 Oct 2009
Posts: 310
Own Kudos [?]: 3796 [0]
Given Kudos: 412
GMAT 1: 530 Q47 V17
GMAT 2: 710 Q50 V36
WE:Business Development (Consulting)
Send PM
GMAT ToolKit User Reviews Badge
Re: How to solve this in 1,5 minute? [#permalink] New post   06 Apr 2010, 12:09
28(1-2+3-4+5-6)=112



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: How to solve this in 1,5 minute? [#permalink]
06 Apr 2010, 12:09
Moderators:
Bunuel
Math Expert
92979 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions