But next minute an ext question from Cambridge 3u is the last question of the 4u paper. The derangement question was one of the ext questions in the perms and combs section of yr 12 Cambridge 3u
Well I'll share a quick rant. I am most certainly fine with them introducing new terminology in an exam paper - they clearly explain what a derangement is. But why the hell was a recurrence relation question sitting there? In what part of the 4U course were students taught how to handle recurrence in perms and combs? The induction question was fine (albeit crazy in that it was only worth 2 marks), and I'm not surprised by recurrence in series (definition of an A.P.), but here? I had nothing to say - at the time I wrote the solutions, all I could think of was why is there something I learnt a mere 1.5 months ago floating around here
Sure, the HSC has been getting dumber. But spiking the difficulty like this is ridiculous in my opinion. I get it, in 2015 they messed up and put a no-brainer part ii) in the perms and combs question. But really? You choose to go from something easy to something insane? Feels like a repeat of the year 2013 with 2U and 3U.
I don't have a problem with them using a textbook question in the exam. Exam writers run out of material eventually, and if you did it before then you hit the jacpot. I'm more fussed about putting something which I don't feel properly belongs in the scope of the course there.