The student revises for 3 hours a day. As exams approach, the student decides to revise for 9 hours a day. What is the opportunity cost of this decision?

The opportunity cost of a decision is what you give up to get something else. In this case, the student is giving up 6 hours of their day to study more.

Step 1: Identify the two choices. In this case, the choices are studying for 3 hours a day or studying for 9 hours a day.

Step 2: Determine what is being given up. Here, the student is giving up 6 hours of their day that could have been spent doing something else.

Step 3: Identify the potential gain. The student is potentially gaining more knowledge or better grades by studying for longer.

Step 4: Weigh the potential gain against what is being given up. This is the opportunity cost. In this case, the opportunity cost of the student's decision to study for 9 hours a day is the 6 hours they are giving up that could have been spent doing something else.