A Fatal Infectious Disease Is Introduced into a Growing Population

Multiple Choice

A fatal infectious disease is introduced into a growing population.Let S denote the number of susceptible people at time t and let I denote the number of infected people at time t.Suppose that, in the absence of the disease, the susceptible population grows at a rate proportional to itself, with constant of proportionality 0.3.People in the infected group die at a rate proportional to the infected population with constant of proportionality -0.2.The rate at which people get infected is proportional to the product of the number of susceptibles and the number of infecteds, with constant of proportionality 0.001.For the initial conditions S = 100 and I = 500, what happens as t starts to increase?

A) S increases and I increases
B) S increases and I decreases
C) S decreases and I increases
D) S decreases and I decreases