How do you answer the scenario questions in order to access all the available marks?

Read the scenario throrughly! No word is there for no reason. Any ambiguities are not an accident, they are there to make you think and question the law. 

Take your time. It is better to have a shorter, well thought through answer that a inchoerant mess!

Start by identifying the law in question. For A-level this will usually be a statute.

Then explain how this corelates to the scenario and use case law to break the statute down into different elements. 

Dont feel the need to definitivley give an answer to the question. Higher marks are given to those who speculate as to the differnet outcomes based on available evidence.