It is currently 18 Feb 2018, 13:40

### 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

Author Message
Intern
Joined: 08 Mar 2017
Posts: 1

### Show Tags

08 Mar 2017, 09:34
Probability of getting 2 heads and 4 tails when flipping a coin 6 times

Sent from my iPhone using GMAT Club Forum mobile app
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 4865
GPA: 3.82

### Show Tags

08 Mar 2017, 20:51
hernandezlarry1234 wrote:
Probability of getting 2 heads and 4 tails when flipping a coin 6 times

Sent from my iPhone using GMAT Club Forum mobile app

When we flip a coin 6 times, there are $$2^6 = 64$$ ways, $$[ H, H, H, H, H, H ], ... , [ T, T, T, T, T, T ]$$ in total.
The number of permutations with $$H, H, T, T, T, T$$ is $$\frac{6!}{4!2!} = \frac{5*6}{1*2} = 15$$.
Hence its probability is $$\frac{15}{64}$$.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself

Re: Probability   [#permalink] 08 Mar 2017, 20:51
Display posts from previous: Sort by