Each of three identical jewelry boxes has two drawers. in each drawer of the first box there is a gold watch. in each drawer of the second box there is a silver watch. in one drawer of the third box there is a gold watch while in the other there is a silver watch. if we select a box at random, open one of the drawers and find it to contain a silver watch, what is the probability that the other drawer has the gold watch?

Let's call the two drawers of the first box, both containing gold.

Let's call the two drawers of the second box, one containing silver, and one containing gold.

Let's call the two drawers of the third box, both containing silver.

If you opened a drawer containing silver, you opened either or .

If you opened , the other drawer is , and thus contains gold.

If you opened , the other drawer is , and thus contains silver.

If you opened , the other drawer is , and thus contains silver.

So, in one case out of three, the other drawer containes gold, and the probability is

the correct answer is the second option