2017 pre-event paper Q4

[PJW]

Only one person attempted this question but this one was pretty good.

I have used this as a basis of this suggested answer which is

• about of the maximum length that could be written in the 30 minutes
  
• rather more considered than could realistically be produced in exam conditions (because I was re-writing the attempt I had the opportunity to extend and refine)
  

Hence it is however another demonstration of the potential content for such a question (from which any actual attempt would  be a sub-set).