There are three chests, each of which contains 100 coins.
One chest has 100 gold coins, one has 100 silver coins, and the third has an equal split of 50 gold coins and 50 silver coins.
Each chest is labeled, but all are labeled incorrectly. You are allowed to pick one coin from just one of the chests and after this you must correctly identify each of the three chests.
What should you do?
Pull one coin out of the chest marked “50 gold and 50 silver coins”. If it’s a gold coin, you know that it’s the chest with 100 gold coins.
The chest labelled “100 gold coins” will then have 100 silver coins and the chest labelled “100 silver coins” will have 50 gold and 50 silver coins.
If the first coin that you pulled out from the chest labelled “50 gold and 50 silver coins” is a silver coin, then you solve the problem in the same general way.