Decision Fatigue

Imagine a situation during exam week: You have been taking exams nonstop for the past two days and will be taking two more exams the next day (one in the morning and one in the afternoon). You plan to attend a career fair the next evening. It is almost midnight and you are very tired, but you have not finished studying for one of the exams. You could stay up longer to prepare for the exams or could stop working and sleep. What would you do in this situation, and why?