@freemo 8?
I suspect unless someone has a background in math, or is good at thinking about this in a more generalized way almost no one is going to get the correct answer.
There is a very formal definition for a hole, and as such a formal/technically correct answer. That said its something someone who doesnt know math could probably reason about if they are particularly good at spatial reasoning.
I am happy to give the answer in DM to anyone who asks.