A Fatal Infectious Disease Is Introduced into a Growing Population

question 45

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

---

Definitions:

Osteoporosis

Disorder characterized by abnormal rarefaction of bone, occurring most frequently in postmenopausal women, sedentary or immobilized individuals, and patients on long-term steroid therapy.

Lactose Intolerance

An inability to digest lactose, a sugar found in milk and dairy products, resulting in digestive discomfort.

Vitamin D

A fat-soluble vitamin that is essential for maintaining healthy bones and teeth, also playing a role in immune system function.

Dairy Products

Foods produced from the milk of mammals, such as cheese, yogurt, and butter, often rich in calcium and vitamin D.