Use bayes theorem to solve this problem, a paper bag contains two red balls and one blue ball. A plastic bag contains three blue
balls and one red ball. A coin is tossed. If it falls heads up, the paper bag is selected and a ball is drawn. If the coin falls tails up, the plastic bag is selected and a ball is drawn. If a red ball is selected what is the probability that it came from the paper bag?
Probability of selecting Paper bag is equivalent to getting a head in coin i.e. 0.5 and probability of selecting Plastic bag is equivalent to getting a tail in coin i.e. 0.5
Probability of getting a red ball from Paper bag
Probability of getting a red ball from Plastic bag
If a red ball is selected Probability that it came from the paper bag