I think I'll probably do the 2 chemistry questions for the NSAA. One of the 12 mark question on last year's paper really confused me and I'm generally better at calculating stuff (with a calculator thank goodness!) than formulating nice answers under time pressure. It just really depends on the questions. The maths for paper 1 is really worrying me as I am not that great at mental maths and that section definitely took me the longest when I did it under timed conditions.