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

It is currently 02 Aug 2015, 16:29
GMAT Club Tests

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 8 students. 4 of them are men and 4 of them are women. If 4

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
avatar
Joined: 26 Mar 2010
Posts: 124
Followers: 2

Kudos [?]: 6 [0], given: 17

There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 06 Apr 2010, 07:30
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

65% (02:08) correct 35% (02:02) wrong based on 17 sessions
There are 8 students. 4 of them are men and 4 of them are women. If 4 students are selected from the 8 students. What is the probability that the number of men is equal to that of women?

A. 18/35
B. 16/35
C. 14/35
D. 13/35
E. 12/35
[Reveal] Spoiler: OA

Last edited by Bunuel on 17 Jun 2015, 00:53, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
Senior Manager
Senior Manager
avatar
Joined: 01 Feb 2010
Posts: 267
Followers: 1

Kudos [?]: 40 [0], given: 2

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 06 Apr 2010, 07:43
utin wrote:
There are 8 students. 4 of them are men and 4 of them are women. If 4 students are selected from the 8 students. What is the probability that the number of men is equal to that of women?

A.18/35 B16/35 C.14/35 D.13/35 E.12/35

According to me answer shall be= 4/8 * 3/7 * 4/6 * 3/5

Were I am wrong???Please explain


probability that the number of men is equal to that of women so 2 men and 2 women =
(4C2*4C2)/8C4 = 18/35 hence A.
Current Student
User avatar
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2799
Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Followers: 198

Kudos [?]: 1187 [0], given: 235

Reviews Badge
Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 06 Apr 2010, 08:05
men= women means 2 men 2 women

total such combinations = 4c2 * 4c2 = 4!/2!.2! * 4!/2!.2! = 6*6

total combinations = 8c4 = 8*7*6*5/4*3*2*1 = 70

so probability = 36/70 = 18/35

hence A
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned :)

Jo Bole So Nihaal , Sat Shri Akaal

:thanks Support GMAT Club by putting a GMAT Club badge on your blog/Facebook :thanks

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
670-to-710-a-long-journey-without-destination-still-happy-141642.html

1 KUDOS received
Manager
Manager
avatar
Joined: 20 Mar 2010
Posts: 84
Followers: 2

Kudos [?]: 62 [1] , given: 1

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 06 Apr 2010, 15:22
1
This post received
KUDOS
utin wrote:
There are 8 students. 4 of them are men and 4 of them are women. If 4 students are selected from the 8 students. What is the probability that the number of men is equal to that of women?

A.18/35 B16/35 C.14/35 D.13/35 E.12/35

According to me answer shall be= 4/8 * 3/7 * 4/6 * 3/5

Were I am wrong???Please explain


You calculated probability of one way in which in which 2 men and 2 women can be selected. But there are 6 different ways in which the selection can happen MMWW, MWMW ,MWWM, WWMM, WMWM,WMMW or 4!/2!2! . So you have to multiply the probability with 6.

6 *4/8 * 3/7 * 4/6 * 3/5 = 18/35
_________________

___________________________________
Please give me kudos if you like my post

Manager
Manager
avatar
Joined: 26 Mar 2010
Posts: 124
Followers: 2

Kudos [?]: 6 [0], given: 17

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 07 Apr 2010, 08:24
crack700 wrote:
utin wrote:
There are 8 students. 4 of them are men and 4 of them are women. If 4 students are selected from the 8 students. What is the probability that the number of men is equal to that of women?

A.18/35 B16/35 C.14/35 D.13/35 E.12/35

According to me answer shall be= 4/8 * 3/7 * 4/6 * 3/5

Were I am wrong???Please explain


You calculated probability of one way in which in which 2 men and 2 women can be selected. But there are 6 different ways in which the selection can happen MMWW, MWMW ,MWWM, WWMM, WMWM,WMMW or 4!/2!2! . So you have to multiply the probability with 6.

6 *4/8 * 3/7 * 4/6 * 3/5 = 18/35




Thanks for clearing my confusion!!! :)...thanks a lot...
Senior Manager
Senior Manager
avatar
Joined: 07 Jan 2010
Posts: 250
Followers: 1

Kudos [?]: 7 [0], given: 16

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 09 Apr 2010, 22:43
the first one that I got right today :)
A i.e. 18/35. I did same as what gurpreet did.
Senior Manager
Senior Manager
User avatar
Affiliations: SPG
Joined: 15 Nov 2006
Posts: 326
Followers: 12

Kudos [?]: 411 [0], given: 20

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 04 Feb 2011, 06:21

let's look at the probability of MMWW.

\(\frac{4}{8}*\frac{3}{7}*\frac{4}{6}*\frac{3}{5} = \frac{3}{35}\)

2 men and 2 women can be arranged in \(^4C2 = 6\) ways.

1. MMWW
2. MWMW
3. MWWM
4. WWMM
5. WMWM
6. WMMW

so total probability \(= \frac{6*3}{35} = \frac{18}{35}\)

_________________

press kudos, if you like the explanation, appreciate the effort or encourage people to respond.

Download the Ultimate SC Flashcards

SVP
SVP
avatar
Joined: 16 Nov 2010
Posts: 1678
Location: United States (IN)
Concentration: Strategy, Technology
Followers: 31

Kudos [?]: 365 [0], given: 36

Premium Member Reviews Badge
Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 09 Jul 2011, 20:23
Probability that the number of men is
equal to that of women = 2 men and 2 women are selected

= 4C2 * 4C2/8C4

= 4!/(2!2!) * 4!/(2!2!)/8!/(4!4!)

= (4*3*2!/(2!2!))^2/(8*7*6 *5*4!/4!/4!)


= 36/(2*35)

= 18/35

Answer - A
_________________

Formula of Life -> Achievement/Potential = k * Happiness (where k is a constant)

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
avatar
Joined: 25 May 2011
Posts: 163
Followers: 2

Kudos [?]: 45 [0], given: 71

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 23 Dec 2011, 11:52
The only possibility is that 2 men and 2 women make the group.

\(P=\frac{C^4_2*C^4_2}{C^8_4}=\frac{18}{35}\)


A
1 KUDOS received
Manager
Manager
avatar
Joined: 26 Apr 2011
Posts: 228
Followers: 0

Kudos [?]: 33 [1] , given: 12

GMAT ToolKit User
Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 26 Dec 2011, 05:01
1
This post received
KUDOS
4C2*4C2/8C4 =18/35
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5716
Followers: 323

Kudos [?]: 63 [0], given: 0

Premium Member
Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 16 Jun 2015, 17:02
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

Expert Post
1 KUDOS received
Director
Director
User avatar
Joined: 08 Jul 2010
Posts: 721
GMAT: INSIGHT
Followers: 19

Kudos [?]: 304 [1] , given: 23

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4 [#permalink] New post 16 Jun 2015, 21:41
1
This post received
KUDOS
Expert's post
utin wrote:
There are 8 students. 4 of them are men and 4 of them are women. If 4 students are selected from the 8 students. What is the probability that the number of men is equal to that of women?

A. 18/35
B. 16/35
C. 14/35
D. 13/35
E. 12/35

According to me answer shall be= 4/8 * 3/7 * 4/6 * 3/5

Were I am wrong???Please explain


METHOD-1:

Favorable outcomes (i.e. No. of Men= No. of Women =2) = 4C2 * 4C2 = 6*6 = 36

Total ways of selecting 4 out of 8 Students = 8C4 = 8! / (4! * 4!) = 70

Probability = 36/70 = 18/35

Answer: Option
[Reveal] Spoiler:
A





METHOD-2: Also see the mistake done by the person who posted this question

Probability of First selected person being Man = 4/8
Probability of Second selected person being Man = 3/7
Probability of First selected person being Woman = 4/6
Probability of Second selected person being Woman = 3/5

i.e. Probability = (4/8)*(3/7)*(4/6)*(3/5) * [4!/(2!*2!)] = 18/35

The important part for the readers is to understand the reason of multiplying [4!/(2!*2!)] here

When we take the probability of each case like we have have taken in this method then it always include ARRANGEMENTS as well and so we have to take every arrangement of the events as well

The arrangement of these 4 events can be done in 4! ways but since the second man can't be selected before 1st so we have to exclude their arrangement by dividing by 2! and similarly since the second Woman can't be selected before 1st so we have to exclude their arrangement by dividing by 2!


Answer: Option
[Reveal] Spoiler:
A

_________________

Prosper!!!

GMATinsight

Bhoopendra Singh and Dr.Sushma Jha

e-mail: info@GMATinsight.com
Call us : +91-9999687183 / 9891333772

http://www.GMATinsight.com/testimonials.html


Contact for One-on-One LIVE Online (SKYPE Based) Quant/Verbal Demo

18 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION
18-online-free-full-length-gmat-cat-practice-tests-link-collection-202780.html

______________________________________________________
Please press the Image if you appreciate this post !!

Re: There are 8 students. 4 of them are men and 4 of them are women. If 4   [#permalink] 16 Jun 2015, 21:41
    Similar topics Author Replies Last post
Similar
Topics:
6 Experts publish their posts in the topic The ratio of men to women in the Snyder community choir is 4 nave 8 12 May 2013, 14:03
2 Experts publish their posts in the topic There are 4 more women than men on Centerville's board of Walkabout 4 07 Dec 2012, 02:20
Experts publish their posts in the topic There are 4 more women than men on Centerville’s board of Bunuel 3 06 May 2012, 08:53
9 Experts publish their posts in the topic A small company employs 3 men and 5 women. If a team of 4 nifoui 6 23 May 2010, 11:11
30 Experts publish their posts in the topic A small company employs 3 men and 5 women. If a team of 4 alimad 16 22 Nov 2007, 18:46
Display posts from previous: Sort by

There are 8 students. 4 of them are men and 4 of them are women. If 4

  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®.