Notes on my questions: A lot of my questions are taken from the book ‘Mathematical Magic Show’ by Martin Gardner – a good read! All other problems are taken from either other (well-known?) sources or my imagination. (I have more coming up…)
Q8 is correct!
For Q9… what if she was interrupted after the first four cards?
I provide three different solutions:
1. If the fly can only travel along the edges, 3 minutes.
2. If the fly can travel through 3D space, sqrt(3) minutes.
3. If the fly can only travel along the faces, sqrt(5) minutes.