[sillypog]

I do think these are reasonable questions, and allowing the candidate to use their own laptop sounds very fair.

One thought though, not necessarily for the poster but for anyone who asks these questions: for the second question, finding common elements of two int arrays, the idiomatic Ruby answer is: x & y

Would you be satisfied with that answer? As a candidate, would I be expected to create a set of tests to ensure that it works, even though this is a standard feature of the language?

If you would not be satisfied with that answer, would you be surprised that a candidate might struggle with an alternative, knowing that they would never use an alternative in their normal coding experience?