A few days ago, walking to take my son to school, I ran into an advertisement, basically that type of wooden blackboard that is placed on the street to draw attention to an establishment, this advertisement said that they sold lunches for $3, I thought which was interesting, i never really eat out, so i thought it was a good price for a complete lunch, i.e. the advert said it included soup, dry (main course which usually contains some protein like chicken, rice and salad ) and also a juice, while I was returning home from school, I kept thinking that $3 was very little money and I wondered if that price would give a positive profit margin to the establishment and how many lunches would they have to sell for $3 dollars? for the business to be profitable, i was really thinking a lot about it, i walked by the front of the establishment and the place looked good, it had nice chairs and tables, the colors were nice and it smelled like the food, you could tell it was a rented place, that is to say, that people were paying rent for the commercial establishment, I kept thinking about the importance of those 3$.