GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 14 Aug 2018, 14:59

### 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

# Which of the following could be the median of a set consisti

Author Message
TAGS:

### Hide Tags

Intern
Joined: 29 Nov 2009
Posts: 26
Location: Bangalore - INDIA
Schools: Duke, NUS,Rutgers
WE 1: Health & Life Science
Which of the following could be the median of a set consisti  [#permalink]

### Show Tags

Updated on: 06 Sep 2013, 07:14
4
24
00:00

Difficulty:

35% (medium)

Question Stats:

69% (01:08) correct 31% (01:00) wrong based on 838 sessions

### HideShow timer Statistics

Which of the following could be the median of a set consisting of 6 different primes?

A. 2
B. 3
C. 9.5
D. 12.5
E. 39

The answer is E, however can any one please explain this problem for me. Why it is 39:?:

Originally posted by divakarbio7 on 22 Feb 2010, 22:48.
Last edited by Narenn on 06 Sep 2013, 07:14, edited 1 time in total.
Always put OA in the spoiler.
Manager
Joined: 26 May 2005
Posts: 193

### Show Tags

22 Feb 2010, 23:45
14
4
median of a set containing 6 different primes
median will be average of 3rd and 4th prime.
All prime greater than 2 are odd. So 3th and 4th primes are odd and their sum will be even and the median will be an integer. 3rd prime will be greater than 2 or 3(first 2 primes)

E
##### General Discussion
Intern
Joined: 29 Nov 2009
Posts: 26
Location: Bangalore - INDIA
Schools: Duke, NUS,Rutgers
WE 1: Health & Life Science

### Show Tags

22 Feb 2010, 23:53

( Why I am confused is as per the rule stated, sum of the odd numbers is even, however 39 is not even)..
Correct me if I am wrong

Thanks Again
Divakar KN
Intern
Joined: 10 Dec 2009
Posts: 1

### Show Tags

23 Feb 2010, 04:44
divakarbio7 wrote:

( Why I am confused is as per the rule stated, sum of the odd numbers is even, however 39 is not even)..
Correct me if I am wrong

Thanks Again
Divakar KN

The median is calculated as the average of the two middle numbers. If the sum of the two numbers is even, average of those numbers can be even or odd. In this case the median is an odd number. Hence 39.
Manager
Joined: 26 May 2005
Posts: 193

### Show Tags

23 Feb 2010, 09:16
divakarbio7 wrote:

( Why I am confused is as per the rule stated, sum of the odd numbers is even, however 39 is not even)..
Correct me if I am wrong

Thanks Again
Divakar KN

median is average of the middle 2 numbers(if the number of the items is even). sum of even, so the median will definitely be integer.

if another choice is 40, then i belive we got to pick up the numbers to see which one is the correct median.
Manager
Joined: 01 Feb 2010
Posts: 239

### Show Tags

23 Feb 2010, 21:59
divakarbio7 wrote:

( Why I am confused is as per the rule stated, sum of the odd numbers is even, however 39 is not even)..
Correct me if I am wrong

Thanks Again
Divakar KN

odd+odd is even and even divided by 2 is always an integer.
Also it can't be 2 or 3 as all primes numbers are different.
Hence best possible choices is 39.
Intern
Joined: 29 Nov 2009
Posts: 26
Location: Bangalore - INDIA
Schools: Duke, NUS,Rutgers
WE 1: Health & Life Science

### Show Tags

30 Mar 2010, 22:13
Which of the following could be the median of a set consisting of 6 different primes?

A> 2
B> 3
C> 9.5
D> 12.5
E> 39

Answer says 39, however i am unable to understand this....
Intern
Joined: 29 Nov 2009
Posts: 26
Location: Bangalore - INDIA
Schools: Duke, NUS,Rutgers
WE 1: Health & Life Science

### Show Tags

30 Mar 2010, 22:20
1
Is this the correct Reasoning?

A> 2 - first prime, hence cant be a median
B> 3 - this option is out, because 3 is not a prime number
Option C & D - 9.5 & 12.5 - cant be the median because in 6 different prime the average for median shouldnt be a decimal (odd+ odd = even) so these options are out

E> 39 - only option left out is this - so it should be the answer!!!!!
Manager
Joined: 01 Feb 2010
Posts: 239

### Show Tags

30 Mar 2010, 22:34
divakarbio7 wrote:
Is this the correct Reasoning?

A> 2 - first prime, hence cant be a median
B> 3 - this option is out, because 3 is not a prime number
Option C & D - 9.5 & 12.5 - cant be the median because in 6 different prime the average for median shouldnt be a decimal (odd+ odd = even) so these options are out

E> 39 - only option left out is this - so it should be the answer!!!!!

Approach is correct. Some modification to your explanation:
A: 2 - first prime, hence cant be a median
B: 3 - Second prime, hence cant be a median
C & D: 9.5 & 12.5 - cannot be the median because in case of 6 different prime the average of two odd numbers cannot be decimal.
E: 39 - only option left out is this - so it should be the answer
Intern
Joined: 29 Nov 2009
Posts: 26
Location: Bangalore - INDIA
Schools: Duke, NUS,Rutgers
WE 1: Health & Life Science

### Show Tags

01 Apr 2010, 05:59
Hi ,

Thank you for the explanation.

Have 2 more questions:
what is the value of n in the list k, n, 12, 6, 17?
a> k< n
b> The median of the numbers in the list is 10

What is the median number of employees per project for the projects at company Z?
a> 25 percent of the projects at company Z have 4 or more employees assigned to each project
b> 35 percent of the projects at company Z have 2 or fewer employees assigned to each project.

i am not able to understand the logic for 2nd problem..answer says C - but note sure why?
Manager
Joined: 20 Apr 2010
Posts: 185
Schools: ISB, HEC, Said

### Show Tags

05 Oct 2010, 04:22
Please post the official explaination E seems to be ambiguis as 39 is not average of any two primes
Math Expert
Joined: 02 Sep 2009
Posts: 47898

### Show Tags

05 Oct 2010, 04:41
prashantbacchewar wrote:
Please post the official explaination E seems to be ambiguis as 39 is not average of any two primes

Actually it is: 37 and 41 --> average = 39.
_________________
Intern
Joined: 16 Jan 2013
Posts: 28
Concentration: Finance, Entrepreneurship
GMAT Date: 08-25-2013
Which of the following could be the median  [#permalink]

### Show Tags

14 Aug 2013, 03:33
Which of the following could be the median of a set consisting of 6 different primes?
(A) 2 (B) 3 (C) 9.5 (D) 12.5 (E) 39

Can somebody plz explain how to proceed.

Verbal Forum Moderator
Joined: 10 Oct 2012
Posts: 615
Re: Which of the following could be the median  [#permalink]

### Show Tags

14 Aug 2013, 03:37
Countdown wrote:
Which of the following could be the median of a set consisting of 6 different primes?
(A) 2 (B) 3 (C) 9.5 (D) 12.5 (E) 39

Can somebody plz explain how to proceed.

Median of 6 primes :$$\frac{odd+odd}{2}$$ = Integer. Options C and D are discarded immediately.

Options A and B can never be the median of 6 primes.

Only option E remains.
_________________
Math Expert
Joined: 02 Sep 2009
Posts: 47898
Re: Which of the following could be the median  [#permalink]

### Show Tags

14 Aug 2013, 03:43
Countdown wrote:
Which of the following could be the median of a set consisting of 6 different primes?
(A) 2 (B) 3 (C) 9.5 (D) 12.5 (E) 39

Can somebody plz explain how to proceed.

Merging similar topics. Please refer to the solutions above.
_________________
Director
Joined: 03 Aug 2012
Posts: 822
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GMAT 2: 680 Q50 V32
GPA: 3.7
WE: Information Technology (Investment Banking)
Re: Which of the following could be the median of a set consisti  [#permalink]

### Show Tags

19 Apr 2014, 23:47
3
This can be done by hit and trial.

(A) 2 (B) 3 (C) 9.5 (D) 12.5 (E) 39

Since all primes should be different, we can take one set as below:

2..3..5..7..11..13

Median (5+7)/2 = 6

Hence, median cannot be less than 6, so reject options A and B

Since primes are odd and the number of terms is 6. So, we will always have median in the below form

(odd+odd)/2 = Even/2 = Integer.

Reject (C) and (D)

Hence (E)
_________________

Rgds,
TGC!
_____________________________________________________________________
I Assisted You => KUDOS Please
_____________________________________________________________________________

Director
Joined: 05 Mar 2015
Posts: 985
Re: Which of the following could be the median of a set consisti  [#permalink]

### Show Tags

22 Dec 2015, 12:37
Countdown wrote:
Which of the following could be the median of a set consisting of 6 different primes?
(A) 2 (B) 3 (C) 9.5 (D) 12.5 (E) 39

Can somebody plz explain how to proceed.

let the consecutive primes be a,b,c,d,e,f
So the median will be (c+d)/2

Looking options we have to find 2*(any options) as sum of two consecutive primes.

becoz median here is avg. of two primes.

1) 2 (ie 2*2=4) so 4 cannot be the sum of middle two primes in a set of six consecutive primes.
2) 3 (3*2=6) same as option 1.
3)9.5(2*9.5=19) so sum can be 17+2 but 17 and 2 were not consecutive.
4)12.5 (2*12.5=25) same as option 3 ie we cannot find any two consecutive primes adding to 25.
5)39 (2*39=78) so here we find 78=37+41 are the two consecutive primes so the set is{29,31,37,41,43,47}

so E is our ans.
Senior Manager
Joined: 15 Jan 2017
Posts: 367
Re: Which of the following could be the median of a set consisti  [#permalink]

### Show Tags

10 Dec 2017, 11:00
Based on options 2,3 are out. 9.5 and 12.5 means odd numbers are divided by two --. 19/2 and 25/2. Both of them have only even numbers as its break up, so have to discard it (after 2 no other even number is prime). leaves us with 39 which is possible (by the break two odd number 7 + 2) so chose that.

Kudos if my explanation made sense to you
Re: Which of the following could be the median of a set consisti &nbs [#permalink] 10 Dec 2017, 11:00
Display posts from previous: Sort by

# Events & Promotions

 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®.