In the game of tennis a player has two serves. If the first serve is successful the game continues. If the first serve is not successful the player serves again. If this second service is successful the game continues. If both serves are unsuccessful the player has served a 'double fault' and loses the point. Gabriella plays tennis. She is successful with 60% of her first serves and 95% of her second serves.

(a) Calculate the probability that Gabriella serves a double fault. If Gabriella is successful with her first serve she has a probability of 0.75 of winning the point. If she is successful with her second serve she has a probability of 0.5 of winning the point.

(b) Calculate the probability that Gabriella wins the point. (MEG)