an urn contains 17 balls marked lose and 3 balls marked win. you and an opponent take turns selecting a single ball at random from the urn without replacement. The person who welects the third win ball wins the game. It does not matter who selected the first two win balls.

I got part a and b but part c is:

If you draw first, what is the probability that you win? hint: you could win on your second, third, fourth,.., or tenth draw, but not on your first.