Studying just the Old Question might not be the best way to study. Only the Important question that you assume or that are the Old papers might not be what you may face in the Exam Hall.
Yes, Important question need to be learned and should be given priority also consider the other question aswell. I will be posting some other questions as well, till then. Here is the Collection of the question form the Trinity College as well as form the HISSAN and HSEB to give you idea about the question pattern