# Probability - fair dice - at least 2 6's in 10 tosses

• Dec 17th 2008, 03:52 AM
lorenz
Probability - fair dice - at least 2 6's in 10 tosses
If a fair dice is tossed 10 times - what is the probability of at least 2 6's?

What is the general 'formula', say I want at least 4 6's etc..

Thanks
• Dec 17th 2008, 03:56 AM
mr fantastic
Quote:

Originally Posted by lorenz
If a fair dice is tossed 10 times - what is the probability of at least 2 6's?

What is the general 'formula', say I want at least 4 6's etc..

Thanks

Let X be the random variable number of 6's.

X ~ Binomial(n = 10, p = 1/6).

Calculate $\Pr(X \geq 2) = 1 - \Pr(X \leq 1) = 1 - \Pr(X = 0) - \Pr(X = 1)$.

Use the formula given here: Binomial Distribution (1 of 3)
• Dec 17th 2008, 04:22 AM
lorenz
Thank you very much