## Problem of the Month

**This Month, Guess One of my Secret Numbers**

Here are the numbers from 1 through 8. I have chosen two of them to be my secret numbers; your job is to figure out ONE of my secret numbers. To do so, you'll need to ask me some yes-or-no questions, which I will answer truthfully.

Here's the catch: each of your questions must be of the form "Is your secret number X?", where X is whatever you want. Once you've asked a question, I will pick one of my two secret numbers, and give the truthful answer for that number.

For example: say my numbers are 2 and 5. If you ask "Is your secret number prime?", I will have to say "Yes", since both of my numbers are prime. But if you ask "Is your secret number even?", I can answer "Yes" or "No" as I please, since one of my numbers is even and one isn't.

Remember, you only need to figure out one of my secret numbers. In order to do that, how many yes-or-no questions will you need?

Send your answers to this puzzle to me (Joseph DiMuro) at joseph.dimuro@biola.edu by April 30th, 2014. No email attachments, please.

## Why Choose Mathematics at Biola?

- Thorough in both educational quality and personal attention to students
- Faculty and students work together to make the study of mathematics a successful and enjoyable learning experience
- Involvement in the Putnam Exam; a nationwide contest for math students
- Experienced faculty who not only teach classes in which they are specialists, but work on research projects with individual students
- Small class sizes
- Readily accessible computing facilities