You are playing Mario Bros. At some point in the game, you have to hit a magic box. The box gives you a mushroom with a probability of .60, a star with a probability of .20, and a flower with a probability of .20. Every time you play, you only hit the magic box once.

a) What is the probability that you will have to play at least 3 times to finally get a star?

b) If you play 10 times, what is the probability that you get a mushroom at least 8 times?