Discrete 1: Easy (Hardest topic was probably those scheduling topics, route inspection I think, though that was simple)
Core 1: Easy (Increasing and decreasing functions a little hard to explain in practice papers but do-able)
Core 2: Easy (Hardest being Binomial Expansion)
Statistics 1: Hardest, though moderately easy (Hardest is probably explaining things without Maths).
Core 3: Moderately easy (Simpsons rule and change in symbol being hardest).
Core 4: Moderately easy (Vectors being difficult to grasp, I'm sure I'll understand it when I revise it though.
To sum it all, most are easy (Easy enough to get an A) but the hardest is probably Stats 1 (it just doesn't interest me).