A Prisoner's Sunday Dilemma
For the last trial, the king used not two, nor three, but nine rooms! The prisoner was told that one room contained a Lady and the other eight were either empty or filled with a tiger. The sign on the Lady's door was true, the signs on room with tigers were false, and empty rooms had signs that were either true or false.
These were the signs:
- The lady is in an odd-numbered room.
- This room is empty.
- Either sign 5 is right or sign 7 is wrong.
- Sign 1 is wrong.
- Either sign 2 or sign 4 is right.
- Sign 3 is wrong.
- 7. The lady is not in room 1.
- This room contains a tiger and room 9 is empty.
- This room contains a tiger and 6 is wrong.
The prisoner studied the nine signs for a while and came to the conclusion that the problem was unsolvable. The king admitted his mistake and told the poor prisoner if room eight was empty or not.
The prisoner needed no more help. He deduced where the Lady was. What about you?
Problem source: The Lady or the Tiger and other Logic Puzzles by Raymond Smullyan. (With thanks to Think Again!)