Buffon's Needle
Problem

Imagine you have a notepad with
the lines ruled 50mm apart. Then
imagine you have to throw a 25mm
needle onto the notepad.

The question usually associated with
this model is :
What is the probability of the needle
falling on one of the ruled lines?

It can be figured by throwing the needle
[n tends to infinity] times and finding
the percentage of successes .

Buffon claimed that the ratio throws:hits
converged to Pi.