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

 It is currently 23 Aug 2016, 19:43

### 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

# M11 #9

Author Message
Manager
Joined: 25 May 2009
Posts: 144
Concentration: Finance
GMAT Date: 12-16-2011
Followers: 3

Kudos [?]: 96 [0], given: 2

### Show Tags

01 Jul 2009, 05:25
Which of the following sets has the same standard deviation as set $$(a, b, c)$$ ?

(C) 2008 GMAT Club - m11#9

* $$(ab, b^2, cb)$$
* $$(2a, b + a, c + b)$$
* $$(0, b + a, c - a)$$
* $$(ab, bc, ac)$$
* $$(ab + c, a(1 + b), b(1+a))$$

[Reveal] Spoiler:
OA=E
Manager
Joined: 11 Apr 2009
Posts: 164
Followers: 2

Kudos [?]: 60 [0], given: 5

### Show Tags

01 Jul 2009, 10:32
SD does not change whenever a constant is added or subtracted to the elements of the set. Here, in E, ab is added to all the elements (a,b,c) which gives:

(a+ab, b+ab, c+ab) = (a(1+b), b(1+a), c+ab).
The order is changed in the options which makes it a bit confusing if you have a lack of time.

Hope this helps.
Manager
Joined: 25 May 2009
Posts: 144
Concentration: Finance
GMAT Date: 12-16-2011
Followers: 3

Kudos [?]: 96 [0], given: 2

### Show Tags

02 Jul 2009, 04:57
Thanks, I get it now.
Re: M11 #9   [#permalink] 02 Jul 2009, 04:57
Similar topics Replies Last post
Similar
Topics:
17 M11 #26 32 24 Jan 2009, 14:18
13 m11#30 20 31 Dec 2008, 22:20
m11,#8 13 11 Nov 2008, 23:35
23 m11#9 9 01 Nov 2008, 08:23
2 M11 #03 2 01 Oct 2008, 15:20
Display posts from previous: Sort by

# M11 #9

Moderator: Bunuel

 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®.