Everyone is capable of excelling in any examination. The first thing that is required is that we understand the material that has been presented to us. This a challenge for the teacher not the student. In my opinion it is the responsibility of the teacher to ensure that all of her students understand the material that has been presented. This is difficult task considering the different learning styles of students, the various levels of cognitive development of the students among other things.
Non the less once a teacher is successful at getting her students to understand then getting them to apply that understanding should be easier.
It is the students responsibility to remember and to become a master of what was taught. This requires that the student do exam type questions (I call this step practice) up until at least a day before the exam. The principle here is what you do not use you will surely lose.
So it is not sufficient for the student to answer questions in class about what was taught (this is how the teacher tests understanding), they must practice what they understood. Especially for those questions that test for how well the student can:
1. apply their knowledge to a new situation,
2. use their knowledge to analyse a situation
3. evaluate situation
4. provide innovative solutions
So the formula for success in any exam from 5th grade to PHD is Understand, Practice until information becomes instinctive, successfully write exams.
