Answering problem questions - holistic approach or in depth?

Just answer the exact question they ask, so don't just recite the law.

There isn't time to recite all the law for the topic the question is addressing, so you will need to choose the correct bits and apply it to the facts.

Don't forget to conclude.

My problem is that I spend too much time on one given problem going in depth at the expense of other problems that are there in the question. As a result, i've been left with little time to deal with the other problems and to conclude. Do you think I should change my tactics and focus more on the different problems and therefore spending less time on one given problem within the question?