What's the probability

[lihinii]

In a restaurant eight plates were broken from monday to friday. What's the probability that no plates will be broken on saturday.
Please help to solve.

Thanks

 

[galactus]

If I am thinking about this correctly, we can use a Poisson probability.

The mean number of plates broken on a given day is $\displaystyle {\lambda}=\frac{8}{5}$.

What is the probability that there are no plates broken on any given day. Say, Saturday.

$\displaystyle P(x)=\frac{{\lambda}^{n}e^{-\lambda}}{n!}$

$\displaystyle P(0)=\frac{(\frac{8}{5})^{0}e^{-\frac{8}{5}}}{0!}=e^{\frac{-8}{5}}\approx .2019$

 

[lihinii]

Thanks sir