Question 1015437: A box contains three drawers. In the first drawer there are 2 gold coins, in the 2nd there are 2 silver coins, and 1 gold coin and 1 silver coin in the 3rd one. A coin is selected at random from a drawer. If the coin selected was a silver, what is the probability that the other coin in that drawer is a gold?
Answer by FrankM(1040)   (Show Source):
You can put this solution on YOUR website! Here are the 3 choices -
Drawer 1 G-G
Drawer 2 S-S
Drawer 3 G-S
You chose S, so there is a 1 in 3 chance the other coin is G.
Because, you could have S(1) or S(2) or S(3) in your hand, so, respectively, the other coin choices are S(2), S(1), or G(3)
Once you draw a coin, and see it is silver, you know you've chosen from Drawer 2 or 3. But as I stated, there are now still 3 possibilities, (1) you've chosen the silver coin from drawer 3, (2) you've chosen the first silver coin from drawer 2 or (3) the second silver coin from drawer 2. Only one of these three silver coins sits with the gold coin.
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