There are 7 billion people on Earth, which is roughly 2^33. Thinking about this number like a computer scientist, only 33 bits (a series of 33 digits, made of 1s and 0s) could uniquely identify each person.

What if we could engineer a series of 33 yes or no questions, and take the answers down as ones and zeros — we could generate a unique code for each person on the planet.

The problem then becomes choosing questions that evenly divide the population 50/50 each time, with (ideally) no “maybes”. Can you think of a question that divides the world in half?

Examples:

- Are you male?
- Do you live in China, India, The United States, Indonesia, Brazil or Pakistan?
- …?