Whenver you do any work, do not have the practice of murmuring in your mind about you much time you had taken to complete your work.
Instead, just think over as to how much time you had been actually involved in your activities.
This is called the power of concentration.
Concentration is a habit by which you are controlling your mind and focussing your mental energies into a single activity without having any botheration about any other activity. This will enhance your vision and you will be able to do the work more effectively.
Students who are reading lessons for months together are getting poor marks whereas some students who are preparing their lessons only for a couple of days are getting good number of marks.
Since they have the power to control their mind and converge their energies into their desired activities, they are able to put their heart and soul into a single activity and they are able to grasp knowledge more than ten to twenty times than an average student.
Learn the power of concentration and learn the tricks in getting in examination and your occupation.