Here's part of the rubric:
So, the way it works is that there are two sections, A and B. Section A has one question in six parts, of which you have to answer four parts. Section B has three questions, of which you have to answer two. Section A has the same weight as a whole as one section B question.
Put rather more simply, you do four questions from section A (worth a twelfth of the total each) and two from section B (worth a third of the total each).
Not hard, is it?
So why, then, did 5 of the 16 candidates answer more than 4 parts of section A? Some of them failed to complete section B because they wasted time answering two parts of section A that they didn't need to answer.
Always read the question paper!