These types of questions aren't about playing a game of catchphrases but are meant to let the candidate shine through demonstrating their thought processes. They are also used as behavioral questions to assess how a candidate deals with situations in which they are not familiar, even if the task itself is incredibly easy or not directly applicable to the job.

You'd be surprised how many people freeze when they are asked to reverse a list of elements.

Another reason to ask fundamental questions is to ensure that an otherwise fit candidate understands the tradeoffs involved.