I don’t think it’s fair to say these examples are know-it-or-not. Sure OP has presented some example solutions, but most of these solutions can be built up fro

I don’t think it’s fair to say these examples are know-it-or-not. Sure OP has presented some example solutions, but most of these solutions can be built up from the basics of tabular data manipulation. Furthermore, there are multiple steps involved that would allow a candidate to show their grasp of these fundamentals and receive help from an interviewer (that doesn’t trivialise the problem).