You have 5 coins and one is double sided Head. If you pick one coin up at random and flip it 5 times and get 5 Heads in a row, what is the probability that you have been flipping the double sided Head coin?

-Thanks.

Printable View

- Feb 18th 2010, 09:49 AMcurious444coin probability
You have 5 coins and one is double sided Head. If you pick one coin up at random and flip it 5 times and get 5 Heads in a row, what is the probability that you have been flipping the double sided Head coin?

-Thanks. - Feb 18th 2010, 11:28 AMicemanfan
I'm going to assume that each coin is chosen with equal probability, which is 0.2.

Then the probability you picked the double head coin is:

$\displaystyle \frac{0.2}{0.2(1 + 4 \cdot 0.5^5)} = \frac{8}{9}$ - Feb 21st 2010, 08:47 AManne