Answer:
The invisible hand concept
Step-by-step explanation:
The invisible hand concept is a metaphor which describes the actions of a person who performs certain tasks for his own benefit but his actions also lead to being a help for the public or a society.
In the scenario, mentioned in the question, Sergio wanted to earn a nice amount of profit for himself by setting up a consulting business. In his effort to do this, he benefited the society by helping them with their computer problems. Hence, this is an example of invisible hand concept.