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

 It is currently 04 May 2015, 10:36

### 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

# John throws a coin until a series of three consecutive heads

Author Message
TAGS:
Director
Joined: 14 Jan 2007
Posts: 780
Followers: 2

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

John throws a coin until a series of three consecutive heads [#permalink]  30 Jun 2007, 08:06
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
John throws a coin until a series of three consecutive heads or three consecutive tails appears. What is the probability that the game will end after the fourth throw?

1. 1/16
2. 2/16
3. 3/16
4. 4/16
5. 6/16

Senior Manager
Joined: 04 Jun 2007
Posts: 348
Followers: 1

Kudos [?]: 15 [0], given: 0

Re: PS Probability [#permalink]  30 Jun 2007, 08:16
vshaunak@gmail.com wrote:
John throws a coin until a series of three consecutive heads or three consecutive tails appears. What is the probability that the game will end after the fourth throw?

1. 1/16
2. 2/16
3. 3/16
4. 4/16
5. 6/16

B for me.

The probability of getting heads=probability of getting tails=1/2

If the game ends after the fourth throw, there are two possibilities.
T,H,H,H or H,T,T,T.

Therefore, required probability= 2 * [(1/2)^4] = 2/16 (or 1/8 )
Re: PS Probability   [#permalink] 30 Jun 2007, 08:16
Similar topics Replies Last post
Similar
Topics:
1 John flips a coin 4 times. What is the probability that he gets heads 5 28 Dec 2014, 18:11
2 John throws a coin until a series of three consecutive heads 1 11 Dec 2012, 11:59
8 John throws a coin until a series of three consecutive heads 19 20 Oct 2008, 04:17
When you throw a coin, the probability of getting head is 1 26 Nov 2005, 06:34
Display posts from previous: Sort by