if the bacteria is tripling every month, that means, their rate of growth is 200% of whatevere their current is, thus
[tex]\bf \qquad \textit{Amount for Exponential Growth}\\\\
A=I(1 + r)^t\qquad
\begin{cases}
A=\textit{accumulated amount}\\
I=\textit{initial amount}\to &2\\
r=rate\to 200\%\to \frac{200}{100}\to &200.00\\
t=\textit{elapsed time}\to &24\\
\end{cases}
\\\\\\
A=2(3)^{24}[/tex]
