5. (Total: 8 points) There are 2 yellow balls, 3 green balls and 4 red balls in a bag. The balls are to be drawn out of the bag randomly without replacement. (a) (2 points) What is the probability that the final drawn ball is red? (b) (3 points) What is the probability that all the yellow balls are drawn before all the red balls are drawn? (c) (3 points) What is the probability that all the yellow balls are drawn before any red balls are drawn?