# Thread: Dice

1. ## Dice

How many times approximately will you have to throw dice to receive the same number three times a row. Calculate the expected value of the amount of throws.

(I´m new in this forum and also non-english speaking so please feel free to correct and help me)

2. Originally Posted by lynch-mob
How many times approximately will you have to throw dice to receive the same number three times a row. Calculate the expected value of the amount of throws.

(I´m new in this forum and also non-english speaking so please feel free to correct and help me)
I'm assuming there are three dice being thrown.

Let X be the random variable number of throws untill the same number is thrown three times in a row.

X follows a geometric distribution.

The probability of success is $p = \left( \frac{1}{6}\right)^3$.

E(X) = 1/p.

3. ## One dice

Originally Posted by mr fantastic
I'm assuming there are three dice being thrown.

Let X be the random variable number of throws untill the same number is thrown three times in a row.

X follows a geometric distribution.

The probability of success is $p = \left( \frac{1}{6}\right)^3$.

E(X) = 1/p.

Im sorry for not being precise. Actually there is only one dice. And the question is how many times will you have to throw that one dice before some of the six numbers will come three times in a row.

Thanks

4. Originally Posted by lynch-mob
Im sorry for not being precise. Actually there is only one dice. And the question is how many times will you have to throw that one dice before some of the six numbers will come three times in a row.

Thanks
I think you change the value of p: $p = \left( \frac{1}{6} \right)^2$. But I will sleep on it .......