Cinema problem, https://www.youtube.com/watch?v=t-IUY6QrJyU

cinema-problem.py

#!usr/bin/env python3


def attendance(price: int):
    """Number of people that will attend for a given price."""
    formula = 120 - ((price - 5) / 0.1) * 15
    return max((formula, 0))


def cost_of_performance(n_people: int) -> float:
    """Cost in dollars of performance."""
    return 180 + 0.04 * n_people


def ticket_sales_of_performance(n_people: int, price: float) -> float:
    """How much does the performance make?"""
    return price * n_people


def profit(price: float) -> float:
    """The amount of profit to expect given a certain price."""
    n_people = attendance(price)
    return ticket_sales_of_performance(n_people, price) - cost_of_performance(n_people)


prices = [x / 10 for x in range(100)]

print(max(prices, key=profit))