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

It is currently 28 Aug 2014, 07:37

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

P(1 defect) = 2 * (999/1000) * (1/1000) = There is

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Eternal Intern
User avatar
Joined: 07 Jun 2003
Posts: 480
Location: Lone Star State
Followers: 1

Kudos [?]: 11 [0], given: 0

GMAT Tests User
P(1 defect) = 2 * (999/1000) * (1/1000) = There is [#permalink] New post 28 Jul 2003, 13:46
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
P(1 defect) = 2 * (999/1000) * (1/1000) =

There is now way this eq up here is right.


. It is about independent events.

A manufacturer makes fastners and sells in packages of two. Suppose the condition of a fastener is independent of the other fastener in the package and in the past the fraction of defective light bulbs is 1/1000. What is the probability that a randomly chosen package has a.) 0 defects b.) Exactly one defect c.) Exactly two defects

_________________

Ride em cowboy


Last edited by Curly05 on 28 Jul 2003, 20:14, edited 1 time in total.
GMAT Instructor
User avatar
Joined: 07 Jul 2003
Posts: 771
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 9

Kudos [?]: 26 [0], given: 0

GMAT Tests User
Re: PS: Easy Prob, but author has error? [#permalink] New post 28 Jul 2003, 14:45
Curly05 wrote:
P(1 defect) = 2 * (999/1000) * (1/1000) =

There is now way this eq up here is right.


. It is about independent events.

A manufacturer makes fastners and sells in packages of two. Suppose the condition of a fastener is independent of the other fastener in the package and in the past the fraction of defective light bulbs is 1/1000. What is the probability that a randomly chosen package has a.) 0 defects b.) Exactly one defect c.) Exactly two defects


Let's say you examine them one by one. The probability that the first is defective is 1/1000 AND the probability that the second is not defective is 999/1000 so the probability of this event is (1/1000)(999/1000). But the defective fastener could be in either the first or second position (i.e., there are two ways that there could be just one defective fastener) so we need to multiply this probability by 2, hence:

Pr(exactly 1 defect) = 2*(1/1000)(999/1000).

_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Eternal Intern
User avatar
Joined: 07 Jun 2003
Posts: 480
Location: Lone Star State
Followers: 1

Kudos [?]: 11 [0], given: 0

GMAT Tests User
Explanation [#permalink] New post 28 Jul 2003, 17:27
So P( 2 defects) , the first defect is reserved for the first slot, and the second defect is reserved for the second slot, thus only one outcome for each slot.

P( 1 defect) , there are two outcomes for defective slot, right- the first or the second. and the prob is etc.

Let's change it around and let's say they want to find the probablilty of defect-free slots.
P( 1 defect-free), Are there are two outcomes for the defect-free slot,right?
Thanks- please explain more Akami
Victor

_________________

Ride em cowboy


Last edited by Curly05 on 29 Jul 2003, 05:10, edited 1 time in total.
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1613
Followers: 5

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

 [#permalink] New post 28 Jul 2003, 23:55
P(a bulb is defect)=0.001
P(a bulb is OK)=0.999

no defects) 0.999*0.999
exactly 1 defect) 0.999*0.001+0.001*0.999=2*0.999*0.001
two defects) 0.001*0.001
Eternal Intern
User avatar
Joined: 07 Jun 2003
Posts: 480
Location: Lone Star State
Followers: 1

Kudos [?]: 11 [0], given: 0

GMAT Tests User
Hey Stolyar [#permalink] New post 29 Jul 2003, 09:02
Stolyar, is your exactly one defect showing that there are four drawings?

VT

_________________

Ride em cowboy

GMAT Instructor
User avatar
Joined: 07 Jul 2003
Posts: 771
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 9

Kudos [?]: 26 [0], given: 0

GMAT Tests User
Re: Hey Stolyar [#permalink] New post 29 Jul 2003, 09:16
Curly05 wrote:
Stolyar, is your exactly one defect showing that there are four drawings?

VT



There are only TWO drawings. Since we are specifically looking at ONE defect, the fact that the defective fastener is picked first is exactly the same as saying the non-defective fastener is picked second. So you can describe the events from either the point of reference using defective fasteners, or non-defective fasteners, but not both.

_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Re: Hey Stolyar   [#permalink] 29 Jul 2003, 09:16
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic If P# = p/(p-1), what is the value of p##? p/(p-1) 1/p p 2-p bmwhype2 2 22 Nov 2007, 14:26
If P# = P / (P -1) , what is P##? P / (P -1) 1/p p 2-p p-1 I bmwhype2 2 19 Oct 2007, 06:55
P1 and P2 are both prime skyjuice 6 11 Oct 2007, 07:33
If P# =P/P-1 what is P##? P/(P-1) 1/P P 2 - P P anonymousegmat 3 23 Jun 2007, 13:29
2 of the 5 production lines are defective. If 2 lines DLMD 4 03 Feb 2005, 11:56
Display posts from previous: Sort by

P(1 defect) = 2 * (999/1000) * (1/1000) = There is

  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®.