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

 It is currently 03 May 2015, 15:39

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

Consider the sets S1 = (1) S2 = (2,3) S3 = (4,5,6) S4 =

Author Message
TAGS:
Manager
Joined: 26 Sep 2004
Posts: 137
Followers: 1

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

Consider the sets S1 = (1) S2 = (2,3) S3 = (4,5,6) S4 = [#permalink]  03 Oct 2004, 08:43
Consider the sets
S1 = (1)
S2 = (2,3)
S3 = (4,5,6)
S4 = (7,8,9,10)

What is the sum of terms in the set S100 ?
Edited :
_________________

Franky
http://franky4gmat.blogspot.com

Last edited by myfrankenstein on 03 Oct 2004, 11:59, edited 1 time in total.
Director
Joined: 16 Jun 2004
Posts: 893
Followers: 2

Kudos [?]: 19 [0], given: 0

Is it 500050.

The approach was..
S1 = (1)
S2 = (2,3)
S3 = (4,5,6)
S4 = (7,8,9,10)
S5 = (11,12,13,14,15)
S6 = (16,17,18,19,20,21)
S7 = (22,23,24,25,26,27,28)
S8 = (29,.....,36)
S9 = (37....)
..
..
S99 = (4852,...) Note: [99*49 +1 = 4852]
S100 = (4951,...) Note: 4852+99 = 4951
Using AP, Sum = (100/2)(2*4951 + 99*1)
= 500050

Last edited by venksune on 03 Oct 2004, 18:01, edited 1 time in total.
Director
Joined: 20 Jul 2004
Posts: 593
Followers: 1

Kudos [?]: 48 [0], given: 0

venksune, I was thinking the same, but did you see that he repeated 3 in S2 and S3.

Your approach would be correct if the wuestion was:
S1 = (0)
S2 = (1,2)
S3 = (3,4,5)
S4 = (6,7,8,9) ...
Director
Joined: 16 Jun 2004
Posts: 893
Followers: 2

Kudos [?]: 19 [0], given: 0

Oops. I did not. I copied his 4 sets blindly when posting. When I did the problem offline, I took the set as you did. I think I will sleep now..
Manager
Joined: 26 Sep 2004
Posts: 137
Followers: 1

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

_________________

Franky
http://franky4gmat.blogspot.com

Director
Joined: 16 Jun 2004
Posts: 893
Followers: 2

Kudos [?]: 19 [0], given: 0

I have edited my post too.
Director
Joined: 31 Aug 2004
Posts: 606
Followers: 3

Kudos [?]: 43 [0], given: 0

Sum of Sn terms = n(n^2+1)/2

S100 = 500050
Similar topics Replies Last post
Similar
Topics:
3 The sequence s1, s2, s3,.....sn,...is such that Sn= 3 26 Apr 2012, 06:14
22 The sequence s1, s2, s3,.....sn,...is such that Sn= (1/n) - 20 17 Aug 2010, 11:46
If s1, s2, s3, ...... is the sequence such that Sn=n/(n+1) 4 01 Sep 2008, 10:31
Find S. (1) S^4=S! (2) S^4!=1 2 14 May 2007, 20:01
If s1, s2, s3, ...... is the sequence such that 1 13 Jun 2005, 14:26
Display posts from previous: Sort by