If a function $P$ represents a system that varies in time, the existence of $\underset{t}{lim}P(t)$ means that the system reaches a steady state or equilibrium. Determine if the following systems in questions $11$ and $12$ reach a steady state. If they do$,$ find that steady state value.

$11.$ The population of a culture of tumor cells is given by $P(t)=\frac{4800t}{t+10}$

$12.$ The population of a colony of squirrels is given by $P(t)=\frac{1600}{2+3e^{-09t}}$