A coin is randomly tossed onto a set of parallel lines. If the
line separation matches the diameter of the coin, what is the
chance that the coin touches a line?
And what if the line separation is different ? Double ? Half
?
If the lines become concentric circles and the gap between the
lines doubles, what is the chance now that the coin touches a
line?
An answer might be guessed at but
the problem is really about justifying that answer.
Do you have a way of visualising it
and could you convince a friend?
If you succeed with that it should be
an easy next step to generalise for a coin of any size.