A King in ancient times wanted to reward one of his brave and faithful knights for his loyal service and bravery in battle. But he was a mischievous King and wanted to reward people who were clever as well as brave and loyal, and so he presented the knight with a puzzle.
He presented the knight with three chests, which were labelled Gold, Lead and Gold And Lead. The King then said that the knight could take just one of the chests, and the knight immediately made a move towards the crate labelled Gold.
However the King stopped the knight and told him the puzzle.
All three chests were labelled incorrectly. Furthermore the knight could examine only one coin from one of the chests before making his decision.
How did the knight determine the correct contents of all three chests and thus take possession of the gold?
The knight should examine one coin from the chest labelled Gold And Lead.
If this is a gold coin then that chest contains gold coins only, as all three are labelled incorrectly. From this the chest marked Gold must contain lead coins only and the chest marked Lead must contain a mixture of coins.
In the same way, if this is a lead coin then that chest contains lead coins only. And then the chest marked Lead must contain gold coins only and the chest marked Gold must contain a mixture of coins.
Would you have walked away with the gold?