🔴 hardmath

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door.

Illustration for riddle: If you're 8 feet away from a door and with each move you advance half the distance to the door. How

You will never reach the door, it will always be half the distance, no matter how small!

Why this works

This riddle plays with the concept of infinite division. Each move you take halves the remaining distance to the door, so if you start at 8 feet away, your first move gets you to 4 feet, then 2 feet, then 1 foot, and so on. However, no matter how many times you halve the distance, there will always be a remaining distance that is half of the previous step, leading to the conclusion that you will never actually reach the door. This paradox illustrates how some problems can lead to seemingly impossible outcomes despite logical steps.

❌

Common Wrong Answers

“4 moves”

This guess assumes that moving half the distance each time will eventually lead to reaching the door, but it overlooks the fact that the distances keep halving infinitely.

“8 moves”

This guess suggests that after 8 moves, you will have covered the 8 feet, but each move only covers half the remaining distance, never actually reaching the door.

“1 move”

This guess implies that one move is sufficient to reach the door, which is incorrect because each move only covers half the distance, so you will still be 4 feet away after the first move.

More math riddles More hard riddles Browse all riddles