I’ve been fascinated recently with questions that are difficult, but don’t require advanced mathematics. I’ve also been fascinated with questions that require algebraic thinking, as opposed to arithmetic thinking. Here is one that I think fits the bill, inspired by a recent walk through the airport:
You walk onto a moving walkway in an airport. There is a person already standing ahead of you on the walkway. What information would you need to determine if you will catch the person before reaching the end of the walkway, and how would you use the information to answer the question.
Sequel: The person in front of you has several pieces of luggage, and you won’t be able to pass them on the moving walkway. What information would you need to determine if it will be faster to walk next to the moving walkway, and how would you use that information to answer the question?