A and B are highly truthful (they each tell the truth : PS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 01:06

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

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

Author Message
CEO
Joined: 15 Aug 2003
Posts: 3460
Followers: 67

Kudos [?]: 861 [0], given: 781

A and B are highly truthful (they each tell the truth [#permalink]

### Show Tags

11 Oct 2003, 10:28
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

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.

thanks
praetorian
Intern
Joined: 16 Sep 2003
Posts: 21
Location: Buffalo (NY)
Followers: 0

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

### Show Tags

11 Oct 2003, 11:02
answer is ---- p(a) + P(b) - P(a)*P(b)
= 3/4 +3/4 -3/4*3/4
=.93
Intern
Joined: 03 May 2003
Posts: 28
Followers: 0

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

Re: PS : Probability ..Rain [#permalink]

### Show Tags

11 Oct 2003, 12:16
praetorian123 wrote:
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.

thanks
praetorian

Also arrive at .9375 by:
1- P(both are not telling the truth) = 1 - (1/4)(1/4) =1 - 1/16 = 15/16
Re: PS : Probability ..Rain   [#permalink] 11 Oct 2003, 12:16
Display posts from previous: Sort by