A tank contains $5000$ L of pure water. Brine that contains $30$ g of salt per liter of water is pumped into the tank at a rate of $25$ L/min. The concentration of salt after $t$ minutes can be shown to be given by:

$$C(t)=\displaystyle \frac{30t}{200+t}$$

What happens to the concentration as $t \to \infty$?

$\displaystyle \lim_{ t \to \infty} C(t)=$ g/L