A circular target of radius three has a bulls-eye of radius one. Given that a randomly thrown dart has hit the target, the probability that the dart hits the bulls-eye is what?

Solution:

P(hit the bull-eye) = S(bull-eye)/S(target) = r^2/R^2 = 1^2/3^2 = 1/9

So the probability that the dart hits the bulls-eye is 1/9