NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 15:17 It is currently 25 Apr 2024, 15:17
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

Jack and Jill work at a hospital with 4 other workers. For a

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
atalpanditgmat
Manager
Manager
Joined: 02 Oct 2012
Status:Working hard to score better on GMAT
Posts: 70
Own Kudos [?]: 579 [10]
Given Kudos: 23
Location: Nepal
Concentration: Finance, Entrepreneurship
GPA: 3.83
WE:Accounting (Consulting)
Send PM
Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   Updated on: 14 Jun 2013, 11:29
1
Kudos
9
Bookmarks
00:00
A
B
C
D
E

Difficulty:

15% (low)

Question Stats:

77% (01:18) correct 23% (01:19) wrong based on 284 sessions
Hide Show timer Statistics
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3
ShowHide Answer
Official Answer
C

Originally posted by atalpanditgmat on 14 Jun 2013, 11:19.
Last edited by Bunuel on 14 Jun 2013, 11:29, edited 2 times in total.
OA added.
Most Helpful Reply
User avatar
nave
Manager
Manager
Joined: 08 Dec 2012
Posts: 55
Own Kudos [?]: 1330 [8]
Given Kudos: 31
Location: United Kingdom
WE:Engineering (Consulting)
Send PM
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   14 Jun 2013, 15:50
4
Kudos
4
Bookmarks
Total number of people = 6

Probability of selecting Jack first and then Jill is \(\frac{1}{6}\)\(*\frac{1}{5}\)\(=\frac{1}{30}\)
Probability of selecting Jill first and then Jack is \(\frac{1}{6}\)\(*\frac{1}{5}\)\(=\frac{1}{30}\)

Therefore probability of selecting Jack and Jill for the review is \(\frac{1}{30}\)\(+\frac{1}{30}\)\(=\frac{1}{15}\)

Answer is C
General Discussion
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92915
Own Kudos [?]: 619017 [2]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   14 Jun 2013, 11:30
2
Kudos
Expert Reply
atalpanditgmat wrote:
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3


1/6C2=1/15.

Answer: C.
avatar
S
redfield
Current Student
Joined: 18 Aug 2014
Posts: 303
Own Kudos [?]: 271 [1]
Given Kudos: 80
Send PM
GMAT ToolKit User Reviews Badge
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   25 Oct 2015, 13:35
Bunuel wrote:
atalpanditgmat wrote:
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3


1/6C2=1/15.

Answer: C.


I just did chance of 1 being selected first time is 1/6 + chance of 1 being selected second time 1/5, turns into 2/30 and reduces to 1/15. Is that the same as 1/6C2=1/15 (my math fundamentals are still lacking a bit)?
User avatar
G
ENGRTOMBA2018
SVP
SVP
Joined: 20 Mar 2014
Posts: 2362
Own Kudos [?]: 3626 [2]
Given Kudos: 816
Concentration: Finance, Strategy
Schools: Kellogg '18 (M)
GMAT 1: 750 Q49 V44
GPA: 3.7
WE:Engineering (Aerospace and Defense)
Send PM
GMAT ToolKit User Reviews Badge
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   25 Oct 2015, 15:07
2
Kudos
redfield wrote:
Bunuel wrote:
atalpanditgmat wrote:
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3


1/6C2=1/15.

Answer: C.


I just did chance of 1 being selected first time is 1/6 + chance of 1 being selected second time 1/5, turns into 2/30 and reduces to 1/15. Is that the same as 1/6C2=1/15 (my math fundamentals are still lacking a bit)?



Yes. nCr = n!/(r!*(n-r)!), thus 6C2 = 6!/(2!*4!) = 15

Thus 1/6C2 = 1/15

The correct way to approach is a follows:

Selecting 1 out of the 2 = 2/6 and then the remaining 1 person out of Jack and Jill = 1/5 , giving you the final probability = 2/6*1/5 = 1/15

Hope this helps.
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92915
Own Kudos [?]: 619017 [2]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
Jack and Jill work at a hospital with 4 other workers. For an internal [#permalink] New post   02 Jun 2016, 04:33
1
Kudos
1
Bookmarks
Expert Reply
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3
User avatar
Divyadisha
Current Student
Joined: 18 Oct 2014
Posts: 680
Own Kudos [?]: 1763 [3]
Given Kudos: 69
Location: United States
GMAT 1: 660 Q49 V31
GPA: 3.98
Send PM
GMAT ToolKit User
Re: Jack and Jill work at a hospital with 4 other workers. For an internal [#permalink] New post   02 Jun 2016, 06:41
3
Kudos
Bunuel wrote:
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3


Total number of ways to choose 2 out of 6 workers= 6!/2!4!= 15

Number of ways to choose both jack and jill= 1

probability= 1/15

C should be the answer
User avatar
L
Skywalker18
Verbal Forum Moderator
Joined: 08 Dec 2013
Status:Greatness begins beyond your comfort zone
Posts: 2101
Own Kudos [?]: 8810 [0]
Given Kudos: 171
Location: India
Concentration: General Management, Strategy
GPA: 3.2
WE:Information Technology (Consulting)
Send PM
GMAT ToolKit User Reviews Badge
Re: Jack and Jill work at a hospital with 4 other workers. For an internal [#permalink] New post   02 Jun 2016, 11:16
Probability that Jack and Jill will both be chosen out of 6 workers
= (2/6)*(1/5)
= 1/15
Answer C
User avatar
D
abhishekdadarwal2009
Director
Director
Joined: 04 Sep 2015
Posts: 552
Own Kudos [?]: 436 [0]
Given Kudos: 123
Location: India
WE:Information Technology (Computer Software)
Send PM
Reviews Badge
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   05 Sep 2020, 07:40
Jack and Jill work at a hospital with 4 other workers. For an internal review, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Jack and Jill will both be chosen?

(A) 1/3
(B) 1/4
(C) 1/15
(D) 3/8
(E) 2/3

IMO C

Sol: Prob of Jack being selected=1/6 then the prob of jill being selected=1/5 (as only 5 are left for second selection)
then the other way jill selected=1/6 and jack selected=1/5

so we get (1/6*1/5)+(1/6*1/5)=(1/30)*2=1/5
User avatar
G
Basshead
Director
Director
Joined: 09 Jan 2020
Posts: 966
Own Kudos [?]: 223 [0]
Given Kudos: 434
Location: United States
Send PM
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   12 Oct 2020, 08:11
Number of ways to choose 2 from 6: 6C2 = 15 ways

Number of ways to choose Jack and Jill from 2: 2C2 = 1 way

= 1/15

Another approach:

Probability of choosing Jack first: 2/6
Probability of choosing Jill second: 1/5

1/6 * 2/5 = 2/30 = 1/15
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32679
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink] New post   06 Nov 2021, 13:20
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 Club Bot
gmatclubot
Re: Jack and Jill work at a hospital with 4 other workers. For a [#permalink]
06 Nov 2021, 13:20
Moderators:
Bunuel
Math Expert
92915 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions