Guess my Number (Posted on 2004-12-20)

	Submitted by Sam
Rating: 3.7647 (17 votes)
Solution:	(Hide)
There are several possible solutions. In general, the object of Alice's question should be to turn a binary question (yes-or-no) into a tertiary question (yes, no or "I don't know"). There are numerous questions of this type, of which my favorite is "I'm thinking of a number between two and three. Is my number higher than yours?" If the hare says yes, his number is one, if he says no, his number is three, and if he says that he doesn't know, his number is two. Federico Kereki also offered an alternative solution: Alice's aim is not to guess the Hare's number but to win a biscuit. In which case, a possible question would be "Is it the case that either 'no' is the answer to this question or you will give me a biscuit?" The Hare can't say "no", as this would be lying (because the first half of the "or" would be true) yet if he says "yes" he will be forced to give Alice a biscuit (the first half of the "or" would be false, so he'd have to make the other half true). These answers, of course, rely on the Hare being truthful.

	Subject	Author	Date
	Puzzle Answer	K Sengupta	2023-02-12 21:45:47
	Yes and know	Math Man	2016-05-08 19:42:15
	another solution	Froggie	2005-03-24 11:41:30
	easy one	ravi	2005-02-22 11:56:23
	re: Another simpler solution?	james	2005-02-22 01:42:36
	think i got it	dev e.	2005-02-07 02:40:19
	re: K.I.S.S.	3llis	2005-01-13 13:57:47
	the rude solution	erdos	2005-01-01 20:11:52
	re(5): Independent solution	Penny	2004-12-27 15:09:35
	re(4): Independent solution	Hugo	2004-12-27 12:12:58
	re(3): Independent solution	Penny	2004-12-27 09:16:15
	re(2): Independent solution	Anna	2004-12-26 23:31:07
	re: Independent solution	Anna	2004-12-26 23:03:29
	re: Only answer.	Ross	2004-12-24 22:15:24
	re: K.I.S.S.	Captain Paradox	2004-12-24 02:02:19
	Only answer.	Vinnie	2004-12-23 20:38:27
	eeeeeeeeeeeeerrrrrrrrrr	megan	2004-12-23 10:23:33
	guess (possible solution)	David	2004-12-23 06:30:24
	re: solution of sorts	Juha S	2004-12-22 20:27:38
	solution of sorts	Juha Salonen	2004-12-22 19:45:52
	re(4): Independent solution	Tristan	2004-12-21 17:41:00
	re: Independent solution	Danny	2004-12-21 15:30:09
	re(3): Independent solution	Fletch	2004-12-21 09:19:07
	re(2): Independent solution	Tristan	2004-12-21 05:41:02
	re: Another simpler solution?	Jer	2004-12-20 18:53:29
	Another simpler solution?	Erik O.	2004-12-20 18:30:06
	K.I.S.S.	Penny	2004-12-20 17:39:51
	re: Alternate possibility	Fletch	2004-12-20 17:11:20
	re: Independent solution	Fletch	2004-12-20 17:04:43
	Independent solution	Tristan	2004-12-20 16:28:09
	Alternate possibility	Penny	2004-12-20 12:28:25
	Impossible solution	Penny	2004-12-20 12:12:31
	Possible solution	Federico Kereki	2004-12-20 11:39:55