Your question is Estimating Employees in a Building. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
If you had to guess how many employees work in a building, what data would you use and why?
Keep your answer structured and practical. Focus on the data sources you would prioritize, how you would triangulate them, and what assumptions you would make if direct headcount data were unavailable.