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

It is currently 25 Oct 2014, 03:39

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

M25 Q10 Set T consists of a certain number of even integers

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 04 Jan 2009
Posts: 12
Schools: not sure
Followers: 0

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

M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 13 Mar 2009, 10:29
3
This post was
BOOKMARKED
Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

(1) All elements of set T are positive

(2) The range of set T is 0
5 KUDOS received
Manager
Manager
avatar
Joined: 07 Jul 2007
Posts: 139
Followers: 1

Kudos [?]: 21 [5] , given: 0

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 16 Mar 2009, 08:28
5
This post received
KUDOS
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


Answer is B).

S1) All elements of set T are positive. - In this case you can have either 0 or positive, SD. (example: (3,3) or (3,6) and so it is not sufficient).

S2) The range of set T is 0, range is (max - min) and so it is zero only if max and min are same (example: 3, 3, 3, 3 set, in this case range will be zero and so standard deviation will be zero too and so S2) answer this question and sufficient.
Manager
Manager
User avatar
Joined: 15 Dec 2008
Posts: 52
Schools: HBS(08) - Ding. HBS, Stanford, Kellogg, Tuck, Stern, all dings. Yale - Withdrew App. Emory Executive -- Accepted, Matriculated, Withdrewed (yes, I spelled it wrong on purpose). ROSS -- GO BLUE 2011.
Followers: 1

Kudos [?]: 37 [0], given: 1

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 17 Mar 2009, 08:46
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


Standard deviation = the square root of something that has been squared, which must be positive, unless of course it's zero.

S1 -- Insufficient. the SD could be 0 or some other number. 0 is not positive, so insufficent to answer the question.

Example --> if the set is {0,0,0,0} SD is zero. If the set is {2,4} SD is 1
S2 -- Sufficient. All the numbers in the set are the same, therefore SD is 0, there the answer is always no.

{0,0,0,0} SD is 0. {2,2} SD is 0....

B
Intern
Intern
avatar
Joined: 06 Mar 2009
Posts: 2
Followers: 0

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

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 20 Mar 2009, 12:09
IMO, the answer should be A. Here's the reasoning :

1. They have clearly given that all the members of the set are positive. Hence, 0 is out (0 does not bear a sign). Even if the members of the set are negative, their deviation will always be +ve. Hence A is sufficient.

2. The members of the set could all be 0. Hence the deviation will be 0. At the same time, all the members of the set can be the same. e.g. 2. In such cases, the range will be 0. So option 2 does not give any additional information. The only scenario that the deviation will not be positive is if the deviation is 0 (in case of all zeros). Hence B is not sufficient.

Ans : A
Director
Director
User avatar
Joined: 01 Apr 2008
Posts: 909
Schools: IIM Lucknow (IPMX) - Class of 2014
Followers: 15

Kudos [?]: 235 [0], given: 18

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 26 Mar 2009, 05:25
IMO C.
1) Set can be {6,6} or {6,9,12} so deviation can be 0 or some +ve num. Not suff.
2) Set can be {0,0} or {6,6} or {-6,0,6,9} => deviation can be zero,-ve or +ve.

Combining, all +ve even numbers divisible by 3 are there and all numbers are same. eg{6,6} => deviation is 0 which is not positive.

What is OA?
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!
1 KUDOS received
CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2500
Followers: 54

Kudos [?]: 512 [1] , given: 19

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 05 Apr 2009, 09:30
1
This post received
KUDOS
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


It should be B however set T cannot have elements other than that are divisible by 3.

Remeber: SD and range can never be -ve.

1: The elements in set T could be [2, 3, 4, 5] or [3, 6, 9, 12, 15] or [3, 3, 3, 3, 3]. The SD could be 0 or +ve.
2: If the range of the set T is 0, then the elements in set T could be [-3, -3, -3, -3] or [3, 3, 3, 3, 3] or [6, 6, 6, 6, 6]. in any case the SD is 0, which is not a positive. Hence suff..
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Manager
Manager
avatar
Joined: 08 Jul 2009
Posts: 171
Followers: 0

Kudos [?]: 21 [0], given: 26

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 05 Jan 2010, 17:48
gmatdreamz wrote:
IMO, the answer should be A. Here's the reasoning :

1. They have clearly given that all the members of the set are positive. Hence, 0 is out (0 does not bear a sign). Even if the members of the set are negative, their deviation will always be +ve. Hence A is sufficient.

2. The members of the set could all be 0. Hence the deviation will be 0. At the same time, all the members of the set can be the same. e.g. 2. In such cases, the range will be 0. So option 2 does not give any additional information. The only scenario that the deviation will not be positive is if the deviation is 0 (in case of all zeros). Hence B is not sufficient.

Ans : A


1, Even if all members of the set are positive, the standard deviation can still be 0.
Expert Post
2 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3614

Kudos [?]: 28941 [2] , given: 2871

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 06 Jan 2010, 04:55
2
This post received
KUDOS
Expert's post
Some tips:

SD\geq0, Standard deviation ALWAYS greater or equal to zero.

Standard deviation equals to zero if and only set consists of identical number(s) (special case set has only one element), eg {2,2,2,2}{-5,-5}{3}.

Range=0 --> SD=0, as when range=0 either we have the set of identical elements or set has only one element.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Intern
Intern
avatar
Joined: 11 Mar 2010
Posts: 4
Followers: 0

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

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 11 Mar 2010, 09:50
RahlowJenkins wrote:
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


Standard deviation = the square root of something that has been squared, which must be positive, unless of course it's zero.

S1 -- Insufficient. the SD could be 0 or some other number. 0 is not positive, so insufficent to answer the question.

Example --> if the set is {0,0,0,0} SD is zero. If the set is {2,4} SD is 1
S2 -- Sufficient. All the numbers in the set are the same, therefore SD is 0, there the answer is always no.

{0,0,0,0} SD is 0. {2,2} SD is 0....

B



The definition SET in mathematics (according to wikipedia ) is:
A set is a collection of distinct objects, considered as an object in its own right.

Note the word "DISTINCT", in the set given example the elements are identical, thus this doesn't fit the definition of a set.

So, the answer should be B, since the elements in the set should be multiples of 6, and they must be distinct.

S1 alone: They can be {6} or {6,12,18}, in the first case SD is 0 and in the second case SD is positive

S2 alone: Range = 0 implies that the max element = min element in the set, since the elements are distinct, the set contains only one element. The SD in that case will always be 0, so not positive.
Senior Manager
Senior Manager
avatar
Joined: 01 Feb 2010
Posts: 268
Followers: 1

Kudos [?]: 35 [0], given: 2

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 12 Mar 2010, 04:58
jenyang5268 wrote:
Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

1. All elements of set T are positive
2. The range of set T is 0

[Reveal] Spoiler: OA
B

Source: GMAT Club Tests - hardest GMAT questions

Can anyone explain this? Thanks!


Its B.

Stmt 1: SD can be +ve or zero so can't decide on SD hence insufficient.
Stmt 2: Range is zero so SD has to be zero so sufficient.
Director
Director
avatar
Joined: 21 Dec 2009
Posts: 589
Concentration: Entrepreneurship, Finance
Followers: 15

Kudos [?]: 292 [0], given: 20

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 18 Mar 2010, 09:19
jenyang5268 wrote:
Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

1. All elements of set T are positive
2. The range of set T is 0


1. 0, 0, are even integers divisible by 3. SD = 0
Also, 0, 6 are even integers divisible by 3. SD is +ve
considering both cases, stmt1 is INSUFF

2. The sets {-6, -6}, {0, 0}, and {12, 12} all have range 0. Irrespective of whether the elements
are +ve or -ve, a unique value in the set gives SD 0.....so, SUFFICIENT
Hence, OA = B.
_________________

KUDOS me if you feel my contribution has helped you.

Manager
Manager
avatar
Joined: 03 Aug 2010
Posts: 107
GMAT Date: 08-08-2011
Followers: 1

Kudos [?]: 16 [0], given: 63

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 16 Mar 2011, 04:19
What does the abbreviation -ve mean?

GMAT TIGER wrote:
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


It should be B however set T cannot have elements other than that are divisible by 3.

Remeber: SD and range can never be -ve.

1: The elements in set T could be [2, 3, 4, 5] or [3, 6, 9, 12, 15] or [3, 3, 3, 3, 3]. The SD could be 0 or +ve.
2: If the range of the set T is 0, then the elements in set T could be [-3, -3, -3, -3] or [3, 3, 3, 3, 3] or [6, 6, 6, 6, 6]. in any case the SD is 0, which is not a positive. Hence suff..
1 KUDOS received
Math Forum Moderator
avatar
Joined: 20 Dec 2010
Posts: 2037
Followers: 128

Kudos [?]: 956 [1] , given: 376

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 16 Mar 2011, 04:29
1
This post received
KUDOS
Yalephd wrote:
What does the abbreviation -ve mean?

GMAT TIGER wrote:
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


It should be B however set T cannot have elements other than that are divisible by 3.

Remeber: SD and range can never be -ve.

1: The elements in set T could be [2, 3, 4, 5] or [3, 6, 9, 12, 15] or [3, 3, 3, 3, 3]. The SD could be 0 or +ve.
2: If the range of the set T is 0, then the elements in set T could be [-3, -3, -3, -3] or [3, 3, 3, 3, 3] or [6, 6, 6, 6, 6]. in any case the SD is 0, which is not a positive. Hence suff..


-ve: Negative. All numbers less than 0 on the number line.
+ve: Positive. All numbers greater than 0 on the number line.

Standard Deviation can never be -ve. It can be 0 or +ve.

Set contains certain number of even integers. Integers should be divisible by 6. Set can have -12,0,6,12,18

5 numbers; all even and divisible by 3.

1. All elements are +ve.

"6,12,18" will result in +ve standard deviation
"6,6,6" will result in 0 standard deviation because all numbers are equal.

Not sufficient.

2. The range of the set is 0.

If the range of a set is 0, all the elements are equal.

Set can be; -12,-12,-12. Standard deviation=0
Or
0,0,0. Standard deviation=0
Or
6,6,6. Standard deviation=0

Since, all the numbers of the set are equal, the standard deviation will be 0.
Sufficient.

Ans: "B"
_________________

~fluke

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 10 Jan 2011
Posts: 244
Location: India
GMAT Date: 07-16-2012
GPA: 3.4
WE: Consulting (Consulting)
Followers: 0

Kudos [?]: 21 [0], given: 25

Reviews Badge
Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 24 Mar 2012, 05:59
patedhav wrote:
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


Answer is B).

S1) All elements of set T are positive. - In this case you can have either 0 or positive, SD. (example: (3,3) or (3,6) and so it is not sufficient).

S2) The range of set T is 0, range is (max - min) and so it is zero only if max and min are same (example: 3, 3, 3, 3 set, in this case range will be zero and so standard deviation will be zero too and so S2) answer this question and sufficient.


why are we asuming that the set contains only positive integers while evaluating st 2.
for example: set can be {-6, 3,3, 6} in this case range is 0 but sandard daviation is ont.

IMO answer should be C
_________________

-------Analyze why option A in SC wrong-------

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3614

Kudos [?]: 28941 [0], given: 2871

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 24 Mar 2012, 06:13
Expert's post
nishtil wrote:
patedhav wrote:
jenyang5268 wrote:
M25, Q10 Data Sufficiency:

Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

S1) All elements of set T are positive
S2) The range of set T is 0

Can anyone explain this? Thanks!


Answer is B).

S1) All elements of set T are positive. - In this case you can have either 0 or positive, SD. (example: (3,3) or (3,6) and so it is not sufficient).

S2) The range of set T is 0, range is (max - min) and so it is zero only if max and min are same (example: 3, 3, 3, 3 set, in this case range will be zero and so standard deviation will be zero too and so S2) answer this question and sufficient.


why are we asuming that the set contains only positive integers while evaluating st 2.
for example: set can be {-6, 3,3, 6} in this case range is 0 but sandard daviation is ont.

IMO answer should be C


One note: the range of {-6, 3, 3, 6} is 12 not 0.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 10 Jan 2011
Posts: 244
Location: India
GMAT Date: 07-16-2012
GPA: 3.4
WE: Consulting (Consulting)
Followers: 0

Kudos [?]: 21 [0], given: 25

Reviews Badge
Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 24 Mar 2012, 09:49
Answer is B).

S1) All elements of set T are positive. - In this case you can have either 0 or positive, SD. (example: (3,3) or (3,6) and so it is not sufficient).

S2) The range of set T is 0, range is (max - min) and so it is zero only if max and min are same (example: 3, 3, 3, 3 set, in this case range will be zero and so standard deviation will be zero too and so S2) answer this question and sufficient.[/quote]

why are we asuming that the set contains only positive integers while evaluating st 2.
for example: set can be {-6, 3,3, 6} in this case range is 0 but sandard daviation is ont.

IMO answer should be C[/quote]

One note: the range of {-6, 3, 3, 6} is 12 not 0.[/quote]

Miss that point.... thanks bunuel..
_________________

-------Analyze why option A in SC wrong-------

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3614

Kudos [?]: 28941 [0], given: 2871

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 27 Mar 2012, 02:46
Expert's post
Set T consists of a certain number of even integers divisible by 3. Is standard deviation of T positive?

The standard deviation of a set shows how much variation there is from the mean, how widespread a given set is. So, a low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values. So, basically we can say that it in a sense measures the distance and the distance can not be negative, which means that the standard deviation of any set is greater than or equal to zero: SD\geq0.

Next, the standard deviation of a set is zero if and only the set consists of identical numbers (or which is the same if the set consists of only one number).

(1) All elements of set T are positive --> set T can be {6, 6} so with the standard deviation equal to zero or {6, 12} so with the standard deviation more than zero. Not sufficient.

(2) The range of set T is 0 --> in order the range to be zero set T should have all identical elements, which means that the standard deviation of the set is zero. Sufficient.

Answer: B.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

Manager
Manager
avatar
Joined: 30 Jul 2011
Posts: 118
Location: United States (NJ)
Concentration: General Management, Finance
GMAT 1: 520 Q40 V21
GPA: 2.95
Followers: 2

Kudos [?]: 17 [0], given: 24

GMAT ToolKit User
Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 30 Mar 2012, 18:42
I'm confused about the question.

It is asking us if the standard deviation is positive. But (within the definition of "standard deviation"), isn't it a given that it already is positive?
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23409
Followers: 3614

Kudos [?]: 28941 [0], given: 2871

Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 31 Mar 2012, 00:43
Expert's post
restore wrote:
I'm confused about the question.

It is asking us if the standard deviation is positive. But (within the definition of "standard deviation"), isn't it a given that it already is positive?


Please read this: m25-q10-data-sufficiency-problem-76533.html#p670261 and this: m25-q10-data-sufficiency-problem-76533.html#p1065546

So, as you can see the standard deviation of any set is greater than or equal to zero: SD\geq{0}.

For more about the Standard Deviation please check: Standard Deviation.

PS questions on SD: ps-questions-about-standard-deviation-85897.html
DS questions on SD: ds-questions-about-standard-deviation-85896.html

PS questions on SD with various tips: ps-questions-about-standard-deviation-85897.html
DS questions on SD with various tips: lately-many-questions-were-asked-about-the-standard-85896.html

Hope it helps.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
25 extra-hard Quant Tests

Get the best GMAT Prep Resources with GMAT Club Premium Membership

BSchool Forum Moderator
User avatar
Joined: 15 Aug 2012
Posts: 103
Location: India
Concentration: Technology, Strategy
Schools: Merage '15 (A)
GPA: 3.6
WE: Consulting (Computer Software)
Followers: 3

Kudos [?]: 37 [0], given: 17

Premium Member
Re: M25 Q10 Set T consists of a certain number of even integers [#permalink] New post 18 Apr 2013, 00:52
Set T consists of a certain number of even integers divisible by 3. Is standard deviation of positive?

1. All elements of set T are positive
2. The range of set T is 0

Case 1:
as SD>= 0, Hence for all positive numbers we can have 2 SD, 0 or +ve. Hence Insufficient

Case 2:
range = 0 => all elements are same hence SD = 0, Sufficient

Hence IMO B
Re: M25 Q10 Set T consists of a certain number of even integers   [#permalink] 18 Apr 2013, 00:52
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic Set T consists of a certain number of even integers divisibl jeetparicha85 1 22 Sep 2013, 18:56
1 Set T consists of a certain number of even integers vishalgc 9 19 Oct 2008, 04:44
Experts publish their posts in the topic Set S consists of even number of integers. Is the median of neelesh 6 24 Dec 2007, 19:42
Set S consists of even number of integers. Is the median of empty_spaces 12 14 Aug 2007, 21:52
11 Experts publish their posts in the topic If set S consists of even number of integers, is the median mirhaque 35 21 Feb 2005, 04:53
Display posts from previous: Sort by

M25 Q10 Set T consists of a certain number of even integers

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page    1   2    Next  [ 22 posts ] 

Moderators: WoundedTiger, Bunuel



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®.