Guess my Number
May 26th, 2007
Well, it is time for a cool and easy riddle. 100 men are each assigned a number between 1-100 with repetitions (e.g. all of them may be assigned the number 17). Each of the men sees all the numbers assigned to all the other 99 men, but none of them sees the number assigned to himself.
Each of them needs to guess his own number (of course no information is exchanged between them – no one hears what others have guessed etc.). What strategy can they employ in order to make sure at least one of them makes a correct guess?
Some followup thoughts:
- Can they make sure more than one person succeeds?
- How many different solutions to the riddle are there (i.e. how many strategies can the men employ?).
Pages: 1 2
May 27th, 2007 at 6:02 pm
Gee, I feel stupid now… I’ve tried thinking about this for over SEVEN minutes and still no solution
I’ll allocate another five minutes for this later and maybe have better luck (maybe just need more coffee)
May 27th, 2007 at 9:00 pm
Hi Matan,
I put the “5 Minute Riddle” icon not in order to make you feel stupid in case you fail to solve it in that amount of time, but to indicate that this riddle is indeed much easier to solve than most others in my site.
The time it takes to solve a riddle varies greatly from one person to the next, and the 5-minute icon is my estimation of the expectancy of the duration of solving the riddle. My estimation of the variance is about 30 minutes. If you fail to solve the riddle in more than one hour, only then should you start feeling stupid (
).
May 28th, 2007 at 10:44 am
IMHO, this riddle is harder much harder than the ants and regexp riddles. Even harder than the rectangles one (though solved it without all that evil vertices and edges shit)
December 15th, 2007 at 5:01 pm
very interesting, but I don’t agree with you
Idetrorce