Scoring trend may be debatable. But luck in precis? How?

The first two questions are purely based on your precis and comprehension skill. You will see an unseen passage and will be asked to summarize it or answer questions based on it. Those answers require skill and nothing else.

The only parts I can imagine where luck plays a role are analogy and word pairs. If you don't know the meaning of the word, its hard to answer(though by no means impossible). Still, you have to attempt 5 out of the 8 parts. This is just how exams are. You won't see everything you have prepared(though we are used to it because our exams contain questions from the books we use). There are people taking 20-25 marks in precis paper and others saying this is all down to luck. Its not.