Question 138
David and Evan are playing a game. Evan thinks of a positive integer $N$ between 1 and 59, inclusive, and David tries to guess it. Each time David makes a guess, Evan will tell him whether the guess is greater than, equal to, or less than $N$. David wants to devise a strategy that will guarantee that he knows $N$ in five guesses. In David's strategy, each guess will be determined only by Evan's responses to any previous guesses (the first guess will always be the same), and David will only guess a number which satisfies each of Evan's responses. How many such strategies are there?
Note: David need not guess $N$ within his five guesses; he just needs to know what $N$ is after five guesses.
Note: David need not guess $N$ within his five guesses; he just needs to know what $N$ is after five guesses.