Well, trying to answer means trying to answer: highlight an approach, try to make a dent, show work even if it doesn't lead you to the final result.
> I generally try to think about a problem before actually, you know, writing stuff down. I can obviously think a lot faster than I can write, so writing down potential approaches when I can't quite see a way to advance from them - or for which I already know that they are wrong - is not really viable.
You are thinking about too simple of a problem.
Any moderatly complex problem won't fit in your head. The traditional approach is to find a path towards what you want to prove, highlight the main lemma and start working on them in order if you can but working backward is fine if you find that easier.
> Giving exam questions for where there isn't a reasonably reachable answer derivable from the taught material is quite cruel.
Life isn't fed to you piece by piece nor is it easy. Advanced questions are hard. That's the point.