Puzzle - how to ensure you get the quarter, not the penny


#1

Originally published at: https://boingboing.net/2018/11/12/puzzle-how-to-ensure-you-get.html


#2

Hey, I’m getting better at these! I got it right away!

…ummm. Carry on?


#3

#4

Ha, I got it right away, too, which must mean it is way easier than most Futility Closet puzzles.


#5

You will retain the penny.


#6

That statement is false because I’m going to throw the penny into a nearby trash can or body of water. I won’t retain it, but neither will I give it to you. Therefore I don’t have to give you either coin.


#7

“The penny may be covered in a deadly poison.”


#8

Only problem there (duh) is that any statement with “may be” is truth-functionally true. At least, harking back to the Monty Hall problem, so long as the person making the statement does not know whether it’s poisoned.


#9

“Give me your lunch money, twerp!”


#10

"hey, thats the quarter I swallowed 12 hrs ago. "


#11

Meh… “you will not give me the penny”.


#12

(gives penny)
Aha! But that means my statement was true, and therefore…
Oh, sorry. Did I forget to mention everything i say is a lie?
Butbutbut… nooooo!


#13

That’ll just make you the recipient of a penny.


#14


Oglaf (often NSFW)


#15

For some reason my answer was “at the end of the game I will have more money than is left on the table” but that amounts to the same thing.


#16

Wait. I get the answer. But there’s still no guarantee you’ll get the quarter. Just because you guessed right, the win is always “I will give you a coin, but it’ll be my choice.” Nothing that was said implies you could CHOOSE which coin you’d get by asking a clever question.

Right answer to the puzzle, but wrong conclusion drawn.

I know, I’m a bore, so damned pedantic. Carry on, clever puzzle solvers.


#17

This topic was automatically closed after 5 days. New replies are no longer allowed.