Logical Puzzle that gives Headache

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Anindya Biswas
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Logical Puzzle that gives Headache

Unread post by Anindya Biswas » Tue Jun 29, 2021 3:49 am

$Alice$ and $Bob$ both choosed a secret number and secretly tells the numbers to $Charlie$. Then they had the following conversations between them (which is not secret) :
  • $Charlie$ : Both of you have choosen a positive integer and one of them is $2$ more than the other.
  • $Alice$ : I don't know $Bob$'s number.
  • $Bob$ : I don't know your number either. Do you know now?
  • $Alice$ : I still have no idea. Do you?
  • $Bob$ : Yes, I know now.
  • $Alice$ : Then so do I.
Find all possible secret number choosen by $Alice$.
"If people do not believe that mathematics is simple, it is only because they do not realize how complicated life is."
John von Neumann

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