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

It is currently 27 Jul 2015, 17:36
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

A doctor claims that 60% of the patients he examines are all

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 01 Apr 2012
Posts: 2
Followers: 0

Kudos [?]: 3 [0], given: 1

A doctor claims that 60% of the patients he examines are all [#permalink] New post 27 Dec 2012, 10:47
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

100% (02:22) correct 0% (00:00) wrong based on 2 sessions
A doctor claims that 60% of the patients he examines are allergic to some type of weeds. What is the probability that exactly three of the next 4 patient he examines are allergic to weeds?

It'll be great if problem is solved step by step with explanation.
Expert Post
2 KUDOS received
Veritas Prep GMAT Instructor
User avatar
Joined: 16 Oct 2010
Posts: 5731
Location: Pune, India
Followers: 1444

Kudos [?]: 7565 [2] , given: 186

Re: A doctor claims that 60% of the patients he examines are all [#permalink] New post 27 Dec 2012, 22:29
2
This post received
KUDOS
Expert's post
mihir66 wrote:
A doctor claims that 60% of the patients he examines are allergic to some type of weeds. What is the probability that exactly three of the next 4 patient he examines are allergic to weeds?

It'll be great if problem is solved step by step with explanation.


The probability of a person being allergic = 6/10
Probability of a person not being allergic = 4/10

Probability of first person being allergic = 6/10
Probability of second person being allergic = 6/10
Probability of third person being allergic = 6/10
Probability of fourth person not being allergic = 4/10

Probability that exactly 3 of the next 4 people are allergic = (6/10)*(6/10)*(6/10)*(4/10)*4
We multiply by 4 because the non allergic person could be first, second or third. So we need to account for all sequences AAAN, AANA, ANAA, NAAA
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199

Veritas Prep Reviews

SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 2046
Concentration: Finance
GMAT 1: 770 Q0 V
Followers: 30

Kudos [?]: 321 [0], given: 355

GMAT ToolKit User
Re: A doctor claims that 60% of the patients he examines are all [#permalink] New post 12 May 2014, 06:45
I would guess this question is just (4)(3^3)(2) / (5^3)(5)=216/625

Therefore answer is A (J/K, would be nice to have some answer choices!)

Cheers!
J :)
Re: A doctor claims that 60% of the patients he examines are all   [#permalink] 12 May 2014, 06:45
    Similar topics Author Replies Last post
Similar
Topics:
14 Experts publish their posts in the topic 60% of all students in a class commute by public transportation. If 30 EgmatQuantExpert 9 13 May 2015, 06:31
15 Experts publish their posts in the topic Kevin drove from A to B at a constant speed of 60 mph. Once he reache Bunuel 9 13 Mar 2015, 06:38
Experts publish their posts in the topic An old man distributed all the gold coins he had to his two Game 3 22 Jun 2014, 10:12
1 In an examination 60% failed in Math and 40% failed in Frenc theGame001 9 01 Aug 2013, 10:35
5 Integer x is equal to the product of all even numbers from 2 to 60, in tejal777 8 13 Sep 2009, 20:56
Display posts from previous: Sort by

A doctor claims that 60% of the patients he examines are all

  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®.