Three identical boxes A, B and C each have two drawers. Box A has a dollar in each drawer, Box B has 5 dollars in each drawer and Box C has 1 dollar in one and 5 in the other. A box is chosen at random and a drawer is opened, and found to contain $5. What is the probability that the other drawer also contains $5?

Question

anonymous · Answer

1/5 or 1/6

deoxna · Answer

The answer in the book is 2/3, and I got 1/3 using a tree diagram which I'm not sure is right.

deoxna · Answer

|dw:1336071434176:dw|Where you are tryin to fin P(5 intersect 5)