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

It is currently 22 Nov 2014, 13:35

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

There are 10 women and 3 men in Room A. One person is picked

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Intern
Intern
avatar
Status: Desperate to breach the 700 barrier
Joined: 24 Jun 2010
Posts: 23
Followers: 0

Kudos [?]: 3 [2] , given: 2

There are 10 women and 3 men in Room A. One person is picked [#permalink] New post 12 Aug 2010, 03:52
2
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

67% (02:12) correct 33% (01:10) wrong based on 55 sessions
There are 10 women and 3 men in Room A. One person is picked at random from Room A and moved to room B, where there are already 3 women and 5 men. If a single person is then to be picked from room B, what is the probability that a woman will be picked?

(A) 13/21
(B) 49/117
(C) 40/117
(D) 15/52
(E) 5/18
[Reveal] Spoiler: OA

Last edited by Bunuel on 16 Sep 2013, 03:02, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
4 KUDOS received
Intern
Intern
avatar
Affiliations: APICS
Joined: 09 Jun 2010
Posts: 14
Followers: 0

Kudos [?]: 9 [4] , given: 2

Re: Probability Question [#permalink] New post 13 Aug 2010, 00:44
4
This post received
KUDOS
Ans: Probability of 49/117


The way I approached it is (probability of Woman from A * probability of woman from B) +( probability of man from A * probability of woman from B)

so its 10/13 * 4/9 + 3/13+3/9

Solving we get 49/117.

Right?

Give a kudos if you like :)

Vivek
Director
Director
avatar
Status: Apply - Last Chance
Affiliations: IIT, Purdue, PhD, TauBetaPi
Joined: 17 Jul 2010
Posts: 693
Schools: Wharton, Sloan, Chicago, Haas
WE 1: 8 years in Oil&Gas
Followers: 14

Kudos [?]: 78 [0], given: 15

Re: Probability Question [#permalink] New post 14 Aug 2010, 01:02
What is the OA?
If M picked from room A, room B probability of picking W is 4/9
If W picked from room A, room B probability of picking W is 3/9

Conditional Probability
P(W in B and M picked in A) = P(W given M picked in A)*P(M picked in A) = 10/13*4/9
P(W in B and W picked in A) = P(W given W picked in A)*P(W picked in A) = 3/13*3/9

Sum 49/117
_________________

Consider kudos, they are good for health

2 KUDOS received
Senior Manager
Senior Manager
User avatar
Status: Final Lap
Joined: 25 Oct 2012
Posts: 294
Concentration: General Management, Entrepreneurship
GPA: 3.54
WE: Project Management (Retail Banking)
Followers: 2

Kudos [?]: 116 [2] , given: 85

Re: Probability Question [#permalink] New post 05 Feb 2013, 16:29
2
This post received
KUDOS
HarishV wrote:
There are 10 women and 3 men in Room A. One person is picked at random from Room A and moved to room B, where there are already 3 women and 5 men. If a single person is then used to be picked from Room B, what is the probability that a woman would be picked.

{Please try solving the problem using the Conditional Probability formula}....Would be very helpful to know how to determine the probability of 2 events when occurring simultaneously}


Using a tree diagram ( see the attachement)

Hence,

WW = \frac{10}{13}*\frac{4}{9}=\frac{40}{117}

MW = \frac{3}{13}*\frac{3}{9}=\frac{9}{117}

Finally, the probability that a woman would be picked is P= \frac{40}{117} + \frac{9}{117}=\frac{49}{117}
Attachments

Prob.png
Prob.png [ 9.74 KiB | Viewed 2140 times ]


_________________

KUDOS is the good manner to help the entire community.

"If you don't change your life, your life will change you"

Intern
Intern
avatar
Joined: 09 Jul 2012
Posts: 11
Followers: 0

Kudos [?]: 1 [0], given: 6

Re: There are 10 women and 3 men in Room A. One person is picked [#permalink] New post 15 Sep 2013, 21:17
The probability that a woman is picked from room A is 10/13
the probability that a woman is picked from room B is 4/9.
Because we are calculating the probability of picking a woman from room A AND then from room B, we need to multiply these two probabilities:
10/13 x 4/9 = 40/117
The probability that a man is picked from room A is 3/13. If that man is then added to room B, this means that there are 3 women and 6 men in room B. So, the probability that a woman is picked from room B is 3/9.
Again, we multiply thse two probabilities:
3/13 x 3/9 = 9/117
To find the total probability that a woman will be picked from room B, we need to take both scenarios into account. In other words, we need to consider the probability of picking a woman and a woman OR a man and a woman. In probabilities, OR means addition. If we add the two probabilities, we get:
40/117 + 9/117 = 49/117
The correct answer is B.
CEO
CEO
User avatar
Joined: 09 Sep 2013
Posts: 3216
Followers: 224

Kudos [?]: 44 [0], given: 0

Premium Member
Re: There are 10 women and 3 men in Room A. One person is picked [#permalink] New post 12 Nov 2014, 00:22
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

Re: There are 10 women and 3 men in Room A. One person is picked   [#permalink] 12 Nov 2014, 00:22
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic A committee is composed of w women and m men. If 3 women and Walkabout 5 20 Dec 2012, 05:30
3 A picnic attracts 240 persons. There are 20 more men than women, and 2 TheRob 4 21 Sep 2009, 08:19
How many more men than women are in the room? el1981 5 20 Sep 2007, 09:37
How many more men than women are there in the room ST 1there mand-y 2 23 Nov 2005, 13:43
Suppose there are 198 men and 2 women in a room. That is, schumacher 7 03 Jan 2005, 13:25
Display posts from previous: Sort by

There are 10 women and 3 men in Room A. One person is picked

  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®.