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

It is currently 28 Jul 2015, 06:20
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

Set S consists of n numbers arranged in ascending order. A

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 04 Jan 2008
Posts: 120
Followers: 2

Kudos [?]: 27 [0], given: 0

Set S consists of n numbers arranged in ascending order. A [#permalink] New post 05 Sep 2008, 20:59
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

59% (02:23) correct 41% (01:10) wrong based on 93 sessions
Set S consists of n numbers arranged in ascending order. A new set is created as follows: each element of set S is increased by a value equal to that number's place within the set (i.e. the lowest number is increased by 1, the second lowest is increased by 2, etc.). By how much is the mean of the new set greater than the mean of the original set ?

(1) Set S consists of 10 elements
(2) The sum of the elements in the original set is 100
[Reveal] Spoiler: OA
Director
Director
avatar
Joined: 23 Sep 2007
Posts: 791
Followers: 5

Kudos [?]: 110 [0], given: 0

Re: Zumit DS 006 [#permalink] New post 05 Sep 2008, 21:23
dancinggeometry wrote:
Set S consists of n numbers arranged in ascending order. A new set is created as follows: each element of set S is increased by a value equal to that number's place within the set (i.e. the lowest number is increased by 1, the second lowest is increased by 2, etc.). By how much is the mean of the new set greater than the mean of the original set ?

(1) Set S consists of 10 elements
(2) The sum of the elements in the original set is 100



A

sum of the original set + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
The average will increase by 5.5
VP
VP
avatar
Joined: 17 Jun 2008
Posts: 1404
Followers: 8

Kudos [?]: 164 [0], given: 0

Re: Zumit DS 006 [#permalink] New post 05 Sep 2008, 21:28
dancinggeometry wrote:
Set S consists of n numbers arranged in ascending order. A new set is created as follows: each element of set S is increased by a value equal to that number's place within the set (i.e. the lowest number is increased by 1, the second lowest is increased by 2, etc.). By how much is the mean of the new set greater than the mean of the original set ?

(1) Set S consists of 10 elements
(2) The sum of the elements in the original set is 100


(1) says n=10 => increased value is n(n+1)/2 =55 when n=10
hence increase in average can be obtained.SUFFI
(2)sum is 100 does not say anythin about n hence INSUFFI
IMOA
_________________

cheers
Its Now Or Never

Intern
Intern
avatar
Joined: 05 Sep 2008
Posts: 13
Followers: 0

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

Re: Zumit DS 006 [#permalink] New post 05 Sep 2008, 21:48
A also.

In order to solve this probem you need to know how many elements are in the set.

st 2 does not show how many elements are in the set so just knowing the sum would not help.
Manager
Manager
User avatar
Joined: 04 Jan 2008
Posts: 120
Followers: 2

Kudos [?]: 27 [0], given: 0

Re: Zumit DS 006 [#permalink] New post 06 Sep 2008, 23:06
OA is A. Bin 3 problem.
Intern
Intern
avatar
Joined: 26 Sep 2012
Posts: 17
Followers: 0

Kudos [?]: 9 [0], given: 1

Re: Set S consists of n numbers arranged in ascending order. A [#permalink] New post 28 May 2013, 23:16
By plugging numbers I discovered that the difference (new median - old median) can be calculated from the formula:
(n+1)/2. Experienced mathematicians must know this effect with sets and the formula.

However, if you are an average GMAT test taker, like me, IMO, the best way to solve was found by gmatnub

gmatnub wrote:
Set S consists of n numbers arranged in ascending order. A new set is created as follows: each
sum of the original set + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
The average will increase by 5.5
Intern
Intern
avatar
Joined: 26 Sep 2012
Posts: 17
Followers: 0

Kudos [?]: 9 [0], given: 1

Re: Set S consists of n numbers arranged in ascending order. A [#permalink] New post 28 May 2013, 23:45
After a while I got the following:

Basically, to obtain a new set we add another set (1, 2, 3, 4, 5, ... n) [Let's name this set as set N] to a first set. As the set N is a set of consecutive numbers, so we can calculate its median. To locate the median we should find the average of the first number and the last number of the set N:
(n+1)/2.
As we know the mean is equal to the median of the same set of consecutive numbers. So, the difference between the mean of a first set and that of a new set can be found if we know the number n of elements of either first or last sets.
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 2046
Concentration: Finance
GMAT 1: 770 Q0 V
Followers: 30

Kudos [?]: 322 [0], given: 355

GMAT ToolKit User
Re: Set S consists of n numbers arranged in ascending order. A [#permalink] New post 12 Oct 2013, 15:35
dancinggeometry wrote:
Set S consists of n numbers arranged in ascending order. A new set is created as follows: each element of set S is increased by a value equal to that number's place within the set (i.e. the lowest number is increased by 1, the second lowest is increased by 2, etc.). By how much is the mean of the new set greater than the mean of the original set ?

(1) Set S consists of 10 elements
(2) The sum of the elements in the original set is 100


Guys remember arranged in ascending order doesn't mean that they are consecutive.
Keep that in mind, GMAT sometimes tries to trick you like this

Good luck
Cheers
J :)
Manager
Manager
avatar
Joined: 27 May 2012
Posts: 213
Followers: 0

Kudos [?]: 52 [0], given: 412

Re: Zumit DS 006 [#permalink] New post 20 Dec 2013, 02:18
gmatnub wrote:
dancinggeometry wrote:
Set S consists of n numbers arranged in ascending order. A new set is created as follows: each element of set S is increased by a value equal to that number's place within the set (i.e. the lowest number is increased by 1, the second lowest is increased by 2, etc.). By how much is the mean of the new set greater than the mean of the original set ?

(1) Set S consists of 10 elements
(2) The sum of the elements in the original set is 100



A

sum of the original set + 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10
The average will increase by 5.5


Just couldn't understand the explanations, here is my small take hope it helps others

average is given by sum of total elements / number of elements

statement 1 : Set S consists of 10 elements

let the sum of the original 10 elements be x , average is \(\frac{x}{10}\)
the new set is formed and its total will be x+55 . Average of new set \(\frac{x+55}{10}\)

Now average increase will be \(\frac{x+55}{10} - \frac{x}{10} = 5.5\)
Hence A is sufficient
Hope it helps.
_________________

- Stne

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5663
Followers: 321

Kudos [?]: 61 [0], given: 0

Premium Member
Re: Set S consists of n numbers arranged in ascending order. A [#permalink] New post 06 Jul 2015, 23:23
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Intern
Intern
avatar
Joined: 21 Jul 2013
Posts: 14
Concentration: Finance
GPA: 3.76
Followers: 0

Kudos [?]: 9 [0], given: 24

GMAT ToolKit User
Re: Set S consists of n numbers arranged in ascending order. A [#permalink] New post 06 Jul 2015, 23:41
guys, i have a question.

"Set S consists of n numbers arranged in ascending order."

It didn't mention that each elements are unique so I picked E because was thinking of the possibility of Set S being "1,1,1,1,1,10,10,10,10,10" or something to that effect.

Is it implied that when the question mentions 'ascending order' meant that each element in that set is unique?
_________________

please give me a kudos if this post was helpful. Thanks! :)

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28728
Followers: 4575

Kudos [?]: 47147 [0], given: 7108

Re: Set S consists of n numbers arranged in ascending order. A [#permalink] New post 07 Jul 2015, 00:12
Expert's post
whitehalo wrote:
guys, i have a question.

"Set S consists of n numbers arranged in ascending order."

It didn't mention that each elements are unique so I picked E because was thinking of the possibility of Set S being "1,1,1,1,1,10,10,10,10,10" or something to that effect.

Is it implied that when the question mentions 'ascending order' meant that each element in that set is unique?


Yes. Ascending order means that each term is greater than the previous one.
_________________

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

PLEASE READ AND FOLLOW: 12 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 ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. Tricky questions from previous years.

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

GMAT Club Premium Membership - big benefits and savings

Re: Set S consists of n numbers arranged in ascending order. A   [#permalink] 07 Jul 2015, 00:12
    Similar topics Author Replies Last post
Similar
Topics:
2 If set S consists of the numbers n, -2, and 4... danzig 2 24 Jun 2013, 11:54
4 Experts publish their posts in the topic If set S consists of the numbers 1, 5, -2, 8, and n, is 0 < Stiv 5 14 May 2012, 11:55
4 Experts publish their posts in the topic Set X consists of different positive numbers arranged in ascending ord enigma123 6 17 Nov 2011, 15:41
If set S consists of the numbers 1, 5, -2, 8 and n, is 0 samramandy 2 21 Aug 2011, 06:46
3 Experts publish their posts in the topic Set A consists of 25 distinct numbers. We pick n numbers Bunuel 16 10 Jan 2010, 23:29
Display posts from previous: Sort by

Set S consists of n numbers arranged in ascending order. A

  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®.