It is currently 13 Dec 2017, 09:14

Decision(s) Day!:

CHAT Rooms | Ross R1 | Kellogg R1 | Darden R1 | Tepper R1


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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

M20-35

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42585

Kudos [?]: 135508 [0], given: 12697

M20-35 [#permalink]

Show Tags

New post 16 Sep 2014, 00:09
Expert's post
9
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

60% (01:02) correct 40% (01:15) wrong based on 128 sessions

HideShow timer Statistics

Kudos [?]: 135508 [0], given: 12697

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42585

Kudos [?]: 135508 [0], given: 12697

Re M20-35 [#permalink]

Show Tags

New post 16 Sep 2014, 00:09
Expert's post
2
This post was
BOOKMARKED
Official Solution:


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
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | 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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135508 [0], given: 12697

Intern
Intern
User avatar
Joined: 25 May 2014
Posts: 47

Kudos [?]: 12 [0], given: 125

GMAT ToolKit User Reviews Badge
Re: M20-35 [#permalink]

Show Tags

New post 28 Jul 2015, 09:05
Bunuel wrote:
Official Solution:


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


Hi Bunuel,
At first i correctly thought that x must be 0 as {\(-1, 0, 0, 1, 3\)} is possible but than I eliminated stmt 1 as 0 can not be written as -0 ( as mentioned -x)
is there a typo in the Q or can we assume both -x and x to be 0
thanks.
_________________

Never Try Quitting, Never Quit Trying

Kudos [?]: 12 [0], given: 125

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42585

Kudos [?]: 135508 [0], given: 12697

Re: M20-35 [#permalink]

Show Tags

New post 29 Jul 2015, 00:18
Ankur9 wrote:
Bunuel wrote:
Official Solution:


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


Hi Bunuel,
At first i correctly thought that x must be 0 as {\(-1, 0, 0, 1, 3\)} is possible but than I eliminated stmt 1 as 0 can not be written as -0 ( as mentioned -x)
is there a typo in the Q or can we assume both -x and x to be 0
thanks.


-0 = 0, so nothing wrong with it.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | 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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135508 [0], given: 12697

Intern
Intern
avatar
Joined: 03 Sep 2014
Posts: 1

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

CAT Tests
Re: M20-35 [#permalink]

Show Tags

New post 12 Oct 2017, 23:58
Hi,

what if x is negative eg ( -4,-1,1,3,4) median here is 0. isnt st1 insufficient?

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

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42585

Kudos [?]: 135508 [0], given: 12697

Re: M20-35 [#permalink]

Show Tags

New post 13 Oct 2017, 00:06
shweta.aarya@gmail.com wrote:
Hi,

what if x is negative eg ( -4,-1,1,3,4) median here is 0. isnt st1 insufficient?


The median of a set with odd number of elements is the middle term, when arranged in ascending/descending order. The media of {-4, -1, 1, 3, 4} is 1, not 0.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | 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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135508 [0], given: 12697

Senior Manager
Senior Manager
User avatar
B
Joined: 08 Jun 2015
Posts: 343

Kudos [?]: 22 [0], given: 101

Location: India
GMAT 1: 640 Q48 V29
Re: M20-35 [#permalink]

Show Tags

New post 31 Oct 2017, 04:28
+1 for A
_________________

" The few , the fearless "

Kudos [?]: 22 [0], given: 101

Manager
Manager
avatar
S
Joined: 03 Apr 2015
Posts: 141

Kudos [?]: -21 [0], given: 60

Reviews Badge
Re: M20-35 [#permalink]

Show Tags

New post 31 Oct 2017, 05:45
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 \(\frac{x}{2}\)

we need a single value of X

condition 1 : 0 is the median then zero is a part of the set mentioned :so x and -x =0 hence an unique answer :sufficient
condition 2: x/2 is median :X can be any any number 0 or 2 itself : so not sufficient

A is correct option

Kudos [?]: -21 [0], given: 60

Manager
Manager
avatar
S
Joined: 22 Apr 2017
Posts: 75

Kudos [?]: 30 [0], given: 57

Location: India
Schools: MBS '20 (S)
GPA: 3.7
GMAT ToolKit User
Re: M20-35 [#permalink]

Show Tags

New post 07 Nov 2017, 23:13
Bunuel wrote:
Official Solution:


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

Hi Bunuel,
Are we missing x=-2 as a probable option? Still statement A is correct but just for clarity..

Kudos [?]: 30 [0], given: 57

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42585

Kudos [?]: 135508 [0], given: 12697

Re: M20-35 [#permalink]

Show Tags

New post 07 Nov 2017, 23:26
ManishKM1 wrote:
Bunuel wrote:
Official Solution:


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

Hi Bunuel,
Are we missing x=-2 as a probable option? Still statement A is correct but just for clarity..


Are you talking about (2)? If x = -2, then the set is \(\{-2, -1, 1, 2, 3\}\). The median = 1, but we are told that it should be x/2 = -1.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | 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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135508 [0], given: 12697

Manager
Manager
avatar
S
Joined: 22 Apr 2017
Posts: 75

Kudos [?]: 30 [0], given: 57

Location: India
Schools: MBS '20 (S)
GPA: 3.7
GMAT ToolKit User
Re: M20-35 [#permalink]

Show Tags

New post 07 Nov 2017, 23:31
Bunuel wrote:
ManishKM1 wrote:
Bunuel wrote:
Official Solution:


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

Hi Bunuel,
Are we missing x=-2 as a probable option? Still statement A is correct but just for clarity..


Are you talking about (2)? If x = -2, then the set is \(\{-2, -1, 1, 2, 3\}\). The median = 1, but we are told that it should be x/2 = -1.



Got it..Thanks a lot..:)

Kudos [?]: 30 [0], given: 57

Intern
Intern
avatar
B
Joined: 17 Mar 2017
Posts: 7

Kudos [?]: 0 [0], given: 14

Premium Member CAT Tests
Re: M20-35 [#permalink]

Show Tags

New post 13 Nov 2017, 06:32
Good afternoon Bunuel,

I was wondering when a set is written, it is all the time written in an ascending order.

In our case: (X<-1<1<3<-X) and thus I understood that -X>3 which mean X=O for (2).

Shall I understood that in a set when a variable is present it is not always presented in ascending order?

Thanks in advance,

Regards,

Kudos [?]: 0 [0], given: 14

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42585

Kudos [?]: 135508 [0], given: 12697

Re: M20-35 [#permalink]

Show Tags

New post 13 Nov 2017, 06:35
Tpral wrote:
Good afternoon Bunuel,

I was wondering when a set is written, it is all the time written in an ascending order.

In our case: (X<-1<1<3<-X) and thus I understood that -X>3 which mean X=O for (2).

Shall I understood that in a set when a variable is present it is not always presented in ascending order?

Thanks in advance,

Regards,


A set, by definition, is a collection of elements without any order. While, a sequence, by definition, is an ordered list of terms.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | 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?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135508 [0], given: 12697

Re: M20-35   [#permalink] 13 Nov 2017, 06:35
Display posts from previous: Sort by

M20-35

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: chetan2u, Bunuel



GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.