A colony of bacteria is growing exponentially according to the function below, where t is in hours. How many hours will it take for the population to grow to 100? Round to the nearest integer and do not include units in your answer.

B(t) = 4 e0.8t

Question

A colony of bacteria is growing exponentially according to the function below, where t is in hours. How many hours will it take for the population to grow to 100? Round to the nearest integer and do not include units in your answer.

B(t) = 4  e0.8t

anonymous · Answer

$$100=4e^{.8t}$$ solve for $t$ in three steps

anonymous · Answer

1) divide by 4
2) write in equivalent logarithmic form
3) divide by $.8$

anonymous · Answer

$$100=4e^{.8t}\
25=e^{.8t}\
\ln(25)=.8t\
\frac{\ln(25)}{.8}=t$$

anonymous · Answer

Thank yooou!  I got 4.02

anonymous · Answer

me too 
yw