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

It is currently 21 Oct 2014, 00:48

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 and B are highly truthful (they each tell the truth

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 60

Kudos [?]: 674 [0], given: 781

A and B are highly truthful (they each tell the truth [#permalink] New post 06 Dec 2003, 16:03
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
27.A and B are highly truthful (they each tell the truth randomly 3/4 of
the time. Also, A's and B's truthfulness are independent. Suppose A and B both look out the window to see what the weather is like. A says, "It's raining." B says, "It's raining." What is the probability that it actually is raining.


my comment : do we need the probability of raining.
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 60

Kudos [?]: 674 [0], given: 781

 [#permalink] New post 06 Dec 2003, 19:32
stoolfi wrote:
15/16, if the chance of rain is 50/50.


could you explain please

whats happens with 50/50

and say.. with rain prob. = 25% and no rain prob. =75%

thanks
praetorian
Director
Director
User avatar
Joined: 28 Oct 2003
Posts: 503
Location: 55405
Followers: 1

Kudos [?]: 5 [0], given: 0

 [#permalink] New post 06 Dec 2003, 20:15
Quote:
could you explain please?


chance of person A lying 1/4
chance of person B lying 1/4

Multiply to find chance of both lying:1/16
15/16, therefore, is the chance of both telling the truth.
Director
Director
User avatar
Joined: 28 Oct 2003
Posts: 503
Location: 55405
Followers: 1

Kudos [?]: 5 [0], given: 0

 [#permalink] New post 06 Dec 2003, 20:24
Quote:
whats happens with 50/50

and say.. with rain prob. = 25% and no rain prob. =75%


I don't know, exactly. But consider this:

Say it rains 1 day out of 160.
If you asked them, every day, whether it was raining, both of them would lie to you 10 times out of 160. So you've got a 1/160 chance of it raining, and an (approximate) 10/160 chance that they tell you it's raining. If they tell you it's raining, they're very probably lying.

I'm sure there's a way to figure this out in greater detail but that will probably not be on the GMAT.
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1613
Followers: 6

Kudos [?]: 52 [0], given: 0

 [#permalink] New post 09 Dec 2003, 04:27
got 15/16
an event is telling the truth.
P=1-P(both lie)=1-1/16=15/16
  [#permalink] 09 Dec 2003, 04:27
    Similar topics Author Replies Last post
Similar
Topics:
The Truth about Vlerick moonsun 1 13 Jun 2013, 13:39
Experts publish their posts in the topic The Truth About the MC Lifestyle domtri33 12 23 Mar 2009, 10:37
Experts publish their posts in the topic Any truth to these ? banerjeea_98 2 23 Sep 2005, 12:23
Experts publish their posts in the topic Any truth to these ? banerjeea_98 1 23 Sep 2005, 12:23
Chances of A saying the truth is 70% and B saying the truth Paul 3 08 Nov 2004, 18:57
Display posts from previous: Sort by

A and B are highly truthful (they each tell the truth

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.