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

 It is currently 17 Apr 2014, 07:57

# STARTING SHORTLY:

### 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

# Probability, tossin a coin

Author Message
Intern
Joined: 28 Nov 2013
Posts: 5
Followers: 0

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

Probability, tossin a coin [#permalink]  02 Apr 2014, 21:03

What is the Probability of tossing a coin five times and having heads appear at least two times?

I tríed to solve it similar like the following but it seems different.

What is the Probability of a coin being tossed three times in a two and landing on heads at least one time?

Landing tails the three times: 1/8

Landing heads at least one time:
1-1/8= 7/8

??

Posted from my mobile device
 Kaplan GMAT Prep Discount Codes Knewton GMAT Discount Codes Manhattan GMAT Discount Codes
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 4171
Location: Pune, India
Followers: 894

Kudos [?]: 3787 [0], given: 148

Re: Probability, tossin a coin [#permalink]  02 Apr 2014, 21:21
Expert's post
UlisesOrdonez wrote:

What is the Probability of tossing a coin five times and having heads appear at least two times?

I tríed to solve it similar like the following but it seems different.

What is the Probability of a coin being tossed three times in a two and landing on heads at least one time?

Landing tails the three times: 1/8

Landing heads at least one time:
1-1/8= 7/8

??

Posted from my mobile device

Total there are 2*2*2*2*2 = 32 outcomes

P(0 Heads) = P(All Tails) = 1/32 (The only possible case is TTTTT)

You multiply by 5 because 1 Head can take 5 places: HTTTT, THTTT, TTHTT, TTTHT, TTTTH

P(At least 2 Heads) = 1 - 1/32 - 5/32 = 26/32
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Save \$100 on Veritas Prep GMAT Courses And Admissions Consulting
Enroll now. Pay later. Take advantage of Veritas Prep's flexible payment plan options.

Veritas Prep Reviews

Re: Probability, tossin a coin   [#permalink] 02 Apr 2014, 21:21
Similar topics Replies Last post
Similar
Topics:
If a certain coin is flipped, the probability that the coin 1 26 Aug 2004, 21:13
If a certain coin is flipped, the probability that the coin 7 05 May 2006, 22:04
If a certain coin is flipped, the probability that the coin 1 12 Nov 2006, 08:49
2 Probability Coins 2 10 Sep 2009, 10:43
1 Coin probability 2 22 Dec 2010, 06:20
Display posts from previous: Sort by