Consider an infection that obeys the SIR model. Given, the average infection length is 10 days and the susceptible population has reached S = 0.8. The government imposes social distancing and mask wearing measures to decrease the probability that a particular infected person infects a particular susceptible. If the goal is to cause the number of infections to decrease, how low does the the probability that a particular individual infects a particular susceptible have to be? Use the differential equations of the SIR model.