7. For a fixed population size, the rate at which a rumor spreads through the population is e at which a proportional to the product of the number of people who have heard the rumor and the number of people who have not heard the rumor. At a high school of 1200 students, when school opens at 8 AM, five students have heard a rumor about you that is embarrassing. An hour later, twenty students have heard the rumor. Mortified, you worry how many students will have heard the rumor when school lets out at 3 PM. How many students know your business?