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

It is currently 19 Oct 2014, 20:25

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

Set B ={4, 6, 8, 10, 12, 14, 16, 18, 20, 22} Set S is formed

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 60

Kudos [?]: 674 [0], given: 781

Set B ={4, 6, 8, 10, 12, 14, 16, 18, 20, 22} Set S is formed [#permalink] New post 09 Oct 2003, 14:39
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Set B ={4, 6, 8, 10, 12, 14, 16, 18, 20, 22}

Set S is formed by taking 8 numbers from Set B.

Whats the standard deviation of S?

a) The mean of S is the same as the mean of B

b) S does not include 22
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1613
Followers: 6

Kudos [?]: 52 [0], given: 0

 [#permalink] New post 09 Oct 2003, 23:19
(1) S can be {6, 8, 10, 12, 14, 16, 18, 20} only; it has a unique SD
(2) S can be {6, 8, 10, 12, 14, 16, 18, 20} or {4, 6, 8, 10, 12, 14, 16, 18} they have the same SD, for they both equally distributed around their means.

Thus D.
Intern
Intern
avatar
Joined: 17 Sep 2003
Posts: 31
Location: Mumbai,India
Followers: 0

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

 [#permalink] New post 10 Oct 2003, 05:24
My working:-

A) The mean of Set B is 13

Therefore, for same mean the sum of set S should be 13x8=104 which means we need to remove two nos with sum 26 from B which has following sets:-
(4,22);(6,20);(8,18);(10,16);(12,14) Therefore a does not give a unique answer

B) S can be formed by removing 22 and any other no. from set B. Therefore, it is also not sufficient to tell SD

Combining A and B we have the set S as Set B- (4,22) . Hence C
_________________

Jazzy bee

CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 60

Kudos [?]: 674 [0], given: 781

 [#permalink] New post 12 Oct 2003, 22:29
stolyar wrote:
(1) S can be {6, 8, 10, 12, 14, 16, 18, 20} only; it has a unique SD
(2) S can be {6, 8, 10, 12, 14, 16, 18, 20} or {4, 6, 8, 10, 12, 14, 16, 18} they have the same SD, for they both equally distributed around their means.

Thus D.



Stolyar

1 is not sufficient we also have S = { 4,8,10,12,14,16,18,22 }
2...i am not sure if its true.. we also have { 4,8,10,12,14,16,18,20 }

I think Jasdeep makes a lot of sense ..nice way to solve the problem
C should be the correct answer

stolyar, comments?

thanks
praetorian
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1613
Followers: 6

Kudos [?]: 52 [0], given: 0

 [#permalink] New post 12 Oct 2003, 22:44
Jasdeep wrote:
My working:-

A) The mean of Set B is 13

Therefore, for same mean the sum of set S should be 13x8=104 which means we need to remove two nos with sum 26 from B which has following sets:-
(4,22);(6,20);(8,18);(10,16);(12,14) Therefore a does not give a unique answer

B) S can be formed by removing 22 and any other no. from set B. Therefore, it is also not sufficient to tell SD

Combining A and B we have the set S as Set B- (4,22) . Hence C


How could I be so stupid? :oops: :toilet :wall
I had a bad day or grow older. Or dealt with the LSAT too long.

(1) agree. removing symmetrical pairs keeps the mean the same
(2) agree. 22 and any other number are out, leaving many different deviations.

combine: S is unique {6, 8, 10, 12, 14, 16, 18, 20} with a unique SD.
agree with C.
  [#permalink] 12 Oct 2003, 22:44
    Similar topics Author Replies Last post
Similar
Topics:
If two numbers are removed from 2, 4, 6, 8, 10, 12, 14, 16, arjtryarjtry 6 04 Sep 2008, 02:37
If two numbers are removed from 2, 4, 6, 8, 10, 12, 14, 16, arjtryarjtry 4 28 Jul 2008, 18:58
What is 10 - 8 + 6 - 4 + .... (-20)? 8 10 12 14 16 Is there bmwhype2 3 22 Oct 2007, 11:49
In the sequence 1, 1/2, 1/4, 1/8, 16, 32,..., each term trickygmat 2 16 Oct 2005, 12:21
Set S contains { 12, 8, 10, 14, 6 } If 2 numbers are removed rxs0005 3 20 Jan 2005, 15:44
Display posts from previous: Sort by

Set B ={4, 6, 8, 10, 12, 14, 16, 18, 20, 22} Set S is formed

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.