My son is playing some game that has lots of logic puzzles. Here was my favorite.
The cops know that one or more of five suspects were in on committing a crime. They know some are lying, but some may be telling the truth. If the cops can figure out who is lying from the following statements, they will release any who are telling the truth and concentrate on the liars. If any are lying in the following statement they are also lying about their innocence.
Suspect 1 says that one person is lying about being involved in the crime.
Suspect 2 says that two people are lying.
Suspect 3 says that three people are lying.
Suspect 4 says that four people are lying.
Suspect 5 says that five people are lying.
How many (and which) suspects are lying and how many are telling the truth?
I loved that this puzzle had such a precise answer.