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

It is currently 23 Oct 2014, 04:29

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

What is the value of x?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
CEO
CEO
User avatar
Joined: 21 Jan 2007
Posts: 2769
Location: New York City
Followers: 8

Kudos [?]: 255 [0], given: 4

What is the value of x? [#permalink] New post 19 Nov 2007, 15:30
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

50% (02:14) correct 50% (01:16) wrong based on 28 sessions
What is the value of x?

(1) The median of set (x, 1, -1, 3, -x) is 0
(2) The median of set (x, 1, -1, 3, -x) is x/2

OPEN DISCUSSION OF THIS QUESTION IS HERE: what-is-the-value-of-x-143334.html
[Reveal] Spoiler: OA

Last edited by Bunuel on 18 Feb 2014, 23:13, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to DS forum.
Kaplan GMAT Prep Discount CodesKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Expert Post
2 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 4877
Location: Pune, India
Followers: 1153

Kudos [?]: 5367 [2] , given: 165

Re: What is x? 1. The median of set (x,1-1,3,-x) is 0 2. The [#permalink] New post 17 Feb 2014, 19:47
2
This post received
KUDOS
Expert's post
bmwhype2 wrote:
What is x?

1. The median of set (x,1-1,3,-x) is 0
2. The median of set (x,1-1,3,-x) is x/2

Please explain your answer


I think the only problem with this question is that it is missing a comma.

What is x?

1. The median of set (x, 1, -1, 3, -x) is 0
2. The median of set (x, 1, -1, 3, -x) is x/2

Solution:

Median of a set is the middle value when the numbers are arranged in increasing order. When there are odd number of numbers e.g. 5 here, the median is simply the 3rd number.

Arranging the set in increasing order: (-1, 1, 3) Now there are two numbers x and -x too in this set which we don't know where to place right now.

1. The median of set (x, 1, -1, 3, -x) is 0
We are given that the median here is 0 which means the third number must be 0. Since we don't have any 0 yet in the set, x (and hence -x too) must be 0.
The set must be (-1, 0, 0, 1, 3).
There is no other way to get a median of 0. Hence x = 0. Sufficient.

2. The median of set (x, 1, -1, 3, -x) is x/2
We saw above that x could be 0 in which case median will be x/2 = 0/2 = 0. So the value x = 0 satisfies this condition.
The median could also be the middle number right now i.e. 1. If x = 2, we get the set (-2, -1, 1, 2, 3) and the median here is 1 which is x/2. Hence x = 2 also satisfies this condition. This means we have two values for x (0 and 2) and not a unique value so this statement alone is not sufficient.

Answer (A)
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save $100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Expert Post
1 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 23393
Followers: 3609

Kudos [?]: 28821 [1] , given: 2852

Re: What is the value of x? [#permalink] New post 18 Feb 2014, 23:14
1
This post received
KUDOS
Expert's post
What is the value of x?

Note that the median of a set with odd number of elements is just the middle element, when arranged in ascending/descending order.

(1) The median of set \{x, -1, 1, 3, -x\} is 0. The median of this set of 5 (odd) elements must be the middle term, hence x=0. Sufficient.

(2) The median of set \{x, -1, 1, 3, -x\} is \frac{x}{2}. It could be that x=0 (in this case the set is {-1, 0, 0, 1, 3}) as well as it could be that x=2 (in this case the set is {-2, -1, 1, 2, 3}). Not sufficient.

Answer: A.

OPEN DISCUSSION OF THIS QUESTION IS HERE: what-is-the-value-of-x-143334.html
_________________

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

CEO
CEO
User avatar
Joined: 29 Aug 2007
Posts: 2500
Followers: 54

Kudos [?]: 512 [0], given: 19

Re: median [#permalink] New post 19 Nov 2007, 17:03
bmwhype2 wrote:
What is x?

1. The median of set (x, 1-1, 3, -x) is 0
2. The median of set (x, 1-1, 3, -x) is x/2

Please explain your answer


hu ... is there any typo?

What is 1-1? is it 1.1 or (1 - 1) = 0?
Director
Director
User avatar
Joined: 13 Dec 2006
Posts: 521
Location: Indonesia
Followers: 6

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

 [#permalink] New post 19 Nov 2007, 17:15
Assuming that 1 and -1 are two different numbers

then Answer is A

1. Median of (-x,1,-1,3,x) = 0 only value of X which will satisfy this equation is 0. as in that case 0 will be the median.... satisfied

2. Median of (-x,1,-1,3,0) = x/2, in this case X can be either 2 or 0, in both the case it will satisfy the median... insufficient.

Now lets assure 1-1=0 is one number, then in that case

1. Median of (-x,0,3,x) = 0, only value of X, whicn can satisfy this equation is 0.... satisfied

2. Median of (-x,0,3,x) = x/2 In this case X can be both 0 and 1 hence insufficient.

In both the cases answer is A

Amar
Manager
Manager
avatar
Joined: 03 Sep 2006
Posts: 233
Followers: 1

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

 [#permalink] New post 19 Nov 2007, 19:04
Amardeep Sharma wrote:

2. Median of (-x,1,-1,3,0) = x/2, in this case X can be either 2 or 0, in both the case it will satisfy the median... insufficient.

Amar


In the Q we have the digit = x, notably (x,1-1,3,-x)
Where is the typo then?

Btw, agree with 1) - Sufficient, but I lost with 2)
Director
Director
avatar
Joined: 09 Aug 2006
Posts: 767
Followers: 1

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

Re: median [#permalink] New post 19 Nov 2007, 22:29
bmwhype2 wrote:
What is x?

1. The median of set (x,1-1,3,-x) is 0
2. The median of set (x,1-1,3,-x) is x/2

Please explain your answer


Stat 1:
There are 5 elements which means the 3rd element has to be 0. -x and -1 have to be the 1st 2 elements. 1 and 3 have to be last 2 elements which leaves x = 0. Suff.

Stat 2:
Same reasoning as 1 but x can = 0 or 1; insuff.


A
Director
Director
User avatar
Joined: 13 Dec 2006
Posts: 521
Location: Indonesia
Followers: 6

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

 [#permalink] New post 20 Nov 2007, 15:47
Whatever wrote:
Amardeep Sharma wrote:

2. Median of (-x,1,-1,3,0) = x/2, in this case X can be either 2 or 0, in both the case it will satisfy the median... insufficient.

Amar


In the Q we have the digit = x, notably (x,1-1,3,-x)
Where is the typo then?

Btw, agree with 1) - Sufficient, but I lost with 2)


Typo is in the question, where the comma is not used between 1 and -1

Amar
Intern
Intern
avatar
Joined: 20 Jan 2013
Posts: 35
Location: India
Concentration: Finance, Entrepreneurship
GMAT Date: 03-14-2014
GPA: 3.42
Followers: 0

Kudos [?]: 16 [0], given: 59

GMAT ToolKit User
Re: What is x? 1. The median of set (x,1-1,3,-x) is 0 2. The [#permalink] New post 17 Feb 2014, 15:14
I'm sorry.. I think I'm missing something?

How can the median of set {−1,0,1,3} be 0? Shouldn't it be .5?
_________________

Best GMAT Resources downloads-
collection-of-the-best-gmat-resources-167295.html#p1329720

May we all emerge victorious :)

Intern
Intern
avatar
Joined: 20 Jan 2013
Posts: 35
Location: India
Concentration: Finance, Entrepreneurship
GMAT Date: 03-14-2014
GPA: 3.42
Followers: 0

Kudos [?]: 16 [0], given: 59

GMAT ToolKit User
Re: What is x? 1. The median of set (x,1-1,3,-x) is 0 2. The [#permalink] New post 17 Feb 2014, 23:59
VeritasPrepKarishma wrote:
bmwhype2 wrote:
What is x?

1. The median of set (x,1-1,3,-x) is 0
2. The median of set (x,1-1,3,-x) is x/2

Please explain your answer


I think the only problem with this question is that it is missing a comma.

What is x?

1. The median of set (x, 1, -1, 3, -x) is 0
2. The median of set (x, 1, -1, 3, -x) is x/2

Solution:

Median of a set is the middle value when the numbers are arranged in increasing order. When there are odd number of numbers e.g. 5 here, the median is simply the 3rd number.

Arranging the set in increasing order: (-1, 1, 3) Now there are two numbers x and -x too in this set which we don't know where to place right now.

1. The median of set (x, 1, -1, 3, -x) is 0
We are given that the median here is 0 which means the third number must be 0. Since we don't have any 0 yet in the set, x (and hence -x too) must be 0.
The set must be (-1, 0, 0, 1, 3).
There is no other way to get a median of 0. Hence x = 0. Sufficient.

2. The median of set (x, 1, -1, 3, -x) is x/2
We saw above that x could be 0 in which case median will be x/2 = 0/2 = 0. So the value x = 0 satisfies this condition.
The median could also be the middle number right now i.e. 1. If x = 2, we get the set (-2, -1, 1, 2, 3) and the median here is 1 which is x/2. Hence x = 2 also satisfies this condition. This means we have two values for x (0 and 2) and not a unique value so this statement alone is not sufficient.

Answer (A)



Thanks Karishma :)
_________________

Best GMAT Resources downloads-
collection-of-the-best-gmat-resources-167295.html#p1329720

May we all emerge victorious :)

Re: What is x? 1. The median of set (x,1-1,3,-x) is 0 2. The   [#permalink] 17 Feb 2014, 23:59
    Similar topics Author Replies Last post
Similar
Topics:
What is the value of │x + 7│? apollo168 3 23 Aug 2006, 04:56
What is the value of │x + 7│? Achilless 2 18 Aug 2006, 21:58
Median: What is value of X humans 4 24 Jun 2006, 02:06
What is the value of x? remgeo 2 08 May 2006, 06:38
What is the value of │x + 7│? M8 7 05 May 2006, 19:46
Display posts from previous: Sort by

What is the value of x?

  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®.