Find all School-related info fast with the new School-Specific MBA Forum

It is currently 28 Aug 2015, 00:24
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Let R be a sum of 30 first members of a row: 1^2, 2^2, 3^2,

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1607
Followers: 6

Kudos [?]: 107 [0], given: 0

Let R be a sum of 30 first members of a row: 1^2, 2^2, 3^2, [#permalink] New post 30 May 2003, 02:00
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Let R be a sum of 30 first members of a row: 1^2, 2^2, 3^2, and so on. Is R odd or even? Why?

:stupid2
Manager
Manager
avatar
Joined: 25 May 2003
Posts: 54
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 30 May 2003, 02:05
R is odd

why?

R=1^2 + 2^2....+30^2
=odd + even ....+even

between 1^2 and 30^2 there is an odd number of squares which are odd, therefore sum of squares is odd
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1607
Followers: 6

Kudos [?]: 107 [0], given: 0

 [#permalink] New post 30 May 2003, 02:09
skoper wrote:
R is odd

why?

R=1^2 + 2^2....+30^2
=odd + even ....+even

between 1^2 and 30^2 there is an odd number of squares which are odd, therefore sum of squares is odd


I have nothing to add :done
Intern
Intern
avatar
Joined: 25 May 2003
Posts: 17
Location: Thailand
Followers: 0

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

explaination [#permalink] New post 01 Jun 2003, 20:47
odd + odd = even ------ sum 14 odd numbers -- (1)

even + odd = odd ------ sum (1) with the remaining odd number,
which is only one --- (3)

even + even = even --------- sum 15 even numbers -- (2)

Thus, (3)+(2) = odd + even = odd

The answer is odd

right and clear ?
explaination   [#permalink] 01 Jun 2003, 20:47
Display posts from previous: Sort by

Let R be a sum of 30 first members of a row: 1^2, 2^2, 3^2,

  Question banks Downloads My Bookmarks Reviews Important topics  


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

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®.