Are you more or less likely to study on a Friday night or a Monday night? Explain this using the term opportunity cost.
There are much more opportunities for a good party/cultural event on Friday. While studying on Friday, the student looses those opportunities. Opportunity cost (the cost of an alternative that must be forgone in order to pursue certain action) on Friday is much higher than on Monday. That is why, it is more likely that the student will study on a Monday night.