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You are investigating a shop robbery. The CCTV footage shows that there was one criminal, but it doesn't show their face. There are 10 suspects and you know that one of them is the criminal. The suspects don't know who the criminal is, except the criminal themselves. The suspects either always tell the truth or always lie. You can ask the whole group a yes/no question and every suspect must answer it. Can you deduce who the criminal is in 2 questions?

Bonus: Suppose now you don't see the individual answers. You are only told at the end how many yes responses each person made. Can you still deduce the criminal?

You are investigating a shop robbery. The CCTV footage shows that there was one criminal, but it doesn't show their face. There are 10 suspects and you know that one of them is the criminal. The suspects don't know who the criminal is, except the criminal themselves. The suspects either always tell the truth or always lie. You can ask the whole group a yes/no question and every suspect must answer it. Can you deduce who the criminal is in 2 questions?

Bonus: Can you do it in just 1 question?

You are investigating a shop robbery. The CCTV footage shows that there was one criminal, but it doesn't show their face. There are 10 suspects and you know that one of them is the criminal. The suspects don't know who the criminal is, except the criminal themselves. The suspects either always tell the truth or always lie. You can ask the whole group a yes/no question and every suspect must answer it. Can you deduce who the criminal is in 2 questions?

You are investigating a shop robbery. The CCTV footage shows that there was one criminal, but it doesn't show their face. There are 10 suspects and you know that one of them is the criminal. The suspects don't know who the criminal is, except the criminal themselves. The suspects either always tell the truth or always lie. You can ask the whole group a yes/no question and every suspect must answer it. Can you deduce who the criminal is in 2 questions?

Bonus: Suppose now you don't see the individual answers. You are only told at the end how many yes responses each person made. Can you still deduce the criminal?