Question 758931
f(t) = 15,000e^-.05t

a) At the beginning t = 0
 f(t) = 15,000e^-.05x0
 f(t) = 15,000e^0
     as e^0 = 1
 f(t) = 15,000
b) after 10 days
 f(t) = 15,000e^-.05 x 10
 f(t) = 15,000e^-.5
 f(t) = 9097.9
c) after 3 weeks
 f(t) = 15,000e^-.05 x 21
 f(t) = 15,000e^-1.05
 f(t) = 5249.
Hope this helps.
:-)