You are trying to guess my favorite number. I tell you it is from 1-100 somewhere and is an interger. You can guess anything you like and I will tell you whether my number is higher or lower then your guess. What is the smallest number of guesses you can make to make sure you will get my number, no matter what it is?

Assume that I don't lie to you about the greater or less than value.

(In reply to The Trick (Full Solution) by DJ)

I might argue that there is nothing the person could say if your first range is the answer. For example, if you were saying "82 to 90" and the number was 87, he would have to say "That's it!", but then you wouldn't know what it was. Or he could say "Both", which would pose another problem...

In any case, this problem is not in "tricks", so you shouldn't be looking for any easy way out in my opinion.

Posted by Gamer on 2003-06-19 05:45:47