STEP downloads (pdf format)

An experiment: if you click below you should see a video of a STEP question being tackled. But note: there is a mistake in the paper III question at about 15 mins (omission of a 3/2 power and a factor of a) which I haven't time to correct at the moment; there is also a mistake in the paper I question at about 10 minutes 40 seconds, where a couple of graphs appear upside down. Sorry about that.