It's something I'd expected someone to know in anything related to data science / machine learning / big data. But if it wasn't a position specific to those fields, then yeah that's that a pretty silly riddle of a question.
edit: even within those fields, it's definitely more of a very-specific-domain-knowledge type of question and not something that I think is worth the time to ask it in a job interview.
edit: even within those fields, it's definitely more of a very-specific-domain-knowledge type of question and not something that I think is worth the time to ask it in a job interview.