Two boxes are used: Box 1 contains 3 red and 2 blue marbles, Box 2 contains 1 red and 4 blue marbles. A box is chosen with probabilities 0.6 for Box 1 and 0.4 for Box 2. A marble drawn is red. What is the probability it came from Box 1?

• A. 0.44
• B. 0.82
• C. 0.60
• D. 0.36

Answer: (B)