The Unexpected Hanging Paradox: A Logic Puzzle

The Classic Paradox

A judge tells a prisoner: "You will be hanged at noon on one of the next seven days. However, you will not know which day it will be until that morning."

Today's Riddle: The Three-Day Version

You're a detective who received this note:

"I will visit the museum on one of the next three days. My visit will be a surprise - you won't be able to know the day of my visit until it happens. Can you catch me?"

The Rules:

Start by considering the last possible day (Day 3). What can you deduce about it?
If you eliminate Day 3, what can you say about Day 2?

Challenge for Blog Readers

Create your own version of the paradox using different scenarios. For example:

Your Task:

  1. Try to resolve the detective riddle above
  2. Create your own version of the paradox
  3. Explain why your version is or isn't truly paradoxical
Click to reveal the logical analysis

Let's analyze the three-day version step by step:

  1. First, consider Day 3:
    • If the visit hasn't happened by Day 2's end, it must be Day 3
    • But then it wouldn't be a surprise
    • So the visit can't be on Day 3
  2. Then, consider Day 2:
    • Since Day 3 is impossible, if it hasn't happened by Day 1's end, it must be Day 2
    • But then it wouldn't be a surprise
    • So the visit can't be on Day 2
  3. Finally, Day 1:
    • Since Days 2 and 3 are impossible, it must be Day 1
    • But then it wouldn't be a surprise
    • So the visit can't be on Day 1 either

The paradox arises because while this reasoning seems sound, the visit could still occur and be a surprise!