Candidates for jobs at American consulting firms are given questions like this one, from a Yale career guide: “How many yellow school busses are used for elementary schools in [city you are recruiting for]?” The guide says that “the approach to the solution is more important than solution itself.”
These market sizing questions “test your thought process, ability to structure, general business and numbers sense.” The guide adds: “There is often a broad range of acceptable answers instead of one correct one.”