Pareto principle
The Pareto principle is a concept introduced by Vilfredo Pareto That shows in many fields, 20% of the subject matter consumes 80% of use. This theorem came from Vilfredo Pareto's research on economics, and buying habits.
Reasoning
changeIt is currently unknown why this phenomenon occurs, or why it is so prominent in every facet of the universe. Some hypothesize that it is a law of physics, that causes everything to act in such a way, While others hypothesize it could simply be a quirk of the human brain, spurring results to occur in this fashion.
Examples
changeIn any given room, 20% of the floor is walked on 80% of the time.
In all languages, 20% of words are used 80% of the time.
20% of criminals commit 80% of crimes.
20% of employees are responsible for 80% of the results.
20% of a store's products make up 80% of sales.