Question: What is the hardest sum you have ever done?

Cathal Cummins answered on 14 Nov 2013:

Well, there are varying degrees of “hardness”. I mean, when I was competing in the International Mathematical Olympiad in secondary school there were really hard questions. Some maths questions are just really long. One calculation last year went on for 10 A4 pages of maths, can you image that — it’s basically short story!!! The maths in that calculation wasn’t that difficult though. I think the most difficult mathematics I’ve ever done was relativistic quantum mechanics; the maths was hard enough but it was trying to wrap my head around what the symbols meant in the physical world that caused me to get confused. The thing about maths is that because it all makes sense, it’s harder to get confused with than something that doesn’t make sense… if that makes sense! 🙂