Growth and Decay in math, Writing the Function as well.

Question

8,000,000 bacterium were introduced to an anti-bacterial agent that reduced the bacteria by a factor of 1/2 every 9 hours. How many bacteria remain after 22 hours? (round to the nearest whole number)

Write the Function that describes this scenario:

Answer 1

This could be written as A(t)=8*10⁶*e^kt where k=(1/9)ln(1/2) or

as A(t)=8*10⁶*(1/2)^t/9

Either way substitute t=22 to get your numerical answer.