A bit that a lot of students get mixed up on the question statements at the end, like 'using the information/data provided' or "with reference to figure x". When it says this, you must refer to the information, data or figure number that is provided or you won't get any marks.
You must also quote the unit that is given.
Some questions might ask you to answer "using your calculation". This is the same - you need to make sure you use your calculation or your previous answer. Even if you couldn't answer the question and you know your answer is wrong, either choose an answer that is easy to complete the calculation with (like 10). If you don't do this - you won't get any marks, but you could still get marks for working out if you do the calculation correctly.