It's good to want to do your best at academics.
Ginger has a final exam coming up in a week for her freshman physics class, which covered 20 chapters of material.
Ginger wants to prepare for the exam.
Ginger studies roughly three chapters each night of the week before the test so that she understands all the material covered that year.
Ginger studies two chapters out of 20 the night before the exam, so she can answer at least some of the questions.
Ginger gets a high grade on the exam and passes the course.
Ginger only gets correct answers on the material she studied, fails the exam, and has to redo the class next semester.