I don't think the fact that the interviewer choose the same quiz all the time is the culprit (on the contrary i would say, because it helps establish a benchmark and understand the pitfalls of that particular question).
The problem is that getting the answer correctly shouldn't be the main goal of the quiz question. Rather, it is the opportunity to see how the candidate think, and how the person is able to work with someone else (aka the interviewer) to solve a given problem.
It could also be a way to make sure the candidate understands a few concepts of its field (complexity, memory pointers, etc).
Mainly what matters is the process, not the solution.
The problem is that getting the answer correctly shouldn't be the main goal of the quiz question. Rather, it is the opportunity to see how the candidate think, and how the person is able to work with someone else (aka the interviewer) to solve a given problem.
It could also be a way to make sure the candidate understands a few concepts of its field (complexity, memory pointers, etc).
Mainly what matters is the process, not the solution.