Calculate the number 7800

A boy asks his dad, “What’s the difference between potential and realistic?” The dad tells him to go ask the rest of his family if they’d sleep with Brad Pitt for a million dollars, and then he’d tell him the answer. The boy goes up to his mom and asks her. She responds, “A million dollars is a lot of money sweetheart. I could send you, your sister, and your brother to great colleges, so sure, I would!” He then goes and asks his sister to which she replies, “Brad Pitt? Hell ya, he’s the hottest guy ever!” Next, the boy asks his brother who replies, “A million dollars? Hell yes I would. I’d be rich!” When the boy excitedly returns to his dad with the family’s responses, the dad says, “Well son, potentially, we have three million dollars. Realistically, we have two sluts and a queer.”