what is the 80/20 rule in studing ?

The 80/20 rule, or the Pareto Principle, states that 80% of your efforts lead to 20% of your results, and vice-versa. This means that 80% of your study book gives you 20% of your knowledge and insights. Also, 20% of your book gives you 80% of your knowledge. The 80/20 rule is also called the Pareto Principle.