Refer to Exercise 45 and determine how long it will take, to the nearest day, for the initial number of people susceptible to decrease to half its amount.

Exercise 45

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 ƒ(t) = 15,000e^-0.05t, where t is time in days.