Bayes' Theorem: Conditional Probability

Katie could put a ball in either Slot A or Slot B and hopes to win a prize. The ball will bounce around and will either land in a winning box or the losing box. Suppose she puts the ball in Slot A 40% of the time; Slot B 60% of the time. If she puts the ball in Slot A, the ball lands in the winning box 15% of the time. If she puts the ball in Slot B, the ball lands in the losing box through the first channel 60% of the time and into the same losing box through the second channel 20% of the time. See illustration below:
Katie won. What is the probability that she put the ball in Slot A?


More Probability of Dependent Events (Conditional Probability) Questions: