Like Kharon says - keep it simple.
The answer to your questions is: No. There are no simple formulae that you can always apply. The exam questions require you to understand the situation and apply your own logic.
Draw a little picture showing what you know. Put a tiny aeroplane on the picture, oriented appropriately. Now the situation and answers should make sense.
(I real life, and with plenty of practice, most people don't think in exam terms, it will be obvious what/where is going on - but if you don't understand the situation, you won't handle it in real life.)