The population of a city doubles during the workday. At the end of the workday, the population decreases
by half. If the population of the city is roughly 4,000,000 people before "rush hour," and the morning rush
hour actually lasts 3 hours, what would be the population 12 hours after the start of rush hour if the
population continued to double every 3 hours? People leave the city for home at the same rate as they
come into the city. If there are 8,000,000 people in the city during the workday, what would be the
population 12 hours after the start of the evening rush hour, which lasts 3 hours, if the population continued
to be cut in half every 3 hours?