During an epidemic, the number of people who have never had the disease and who are not immune (they are susceptible) decreases exponentially according to the function where t is time in days.

Question

f(t)=15,000e^-.05t
Determine how long it will take for the initial number of people susceptible to decrease to half the amount

Answer 1

you want t such that

e^-.05t = 0.5
-.05t = ln(0.5)
t = ln(0.5)/(-.05) = 13.86