We answer the first part of the problem here.
P = 50000, so our differential equation becomes:
Solving using Scientific Notebook gives us the number of people affected at time t:
[We'll see how to solve this kind of problem in the Separation of Variables section.]
Now, we are told that at t = 10, A = 1000.
So now we can substitute and solve for c:
c = 4. 6416 × 10-6
So substituting this value of c into the expression for A(t) gives us: