A large brine tank containing a solution of salt and water is being diluted with fresh water.
The relationship between the elapsed time, $t$, in hours, after the dilution begins, and the concentration of salt in the tank, $S(t)$, in grams per liter $(\text{g/l})$, is modeled by the following function.
$ S(t)=600\cdot e^{\large{-0.3t}}$
**How many hours will it take for the concentration of salt to decrease to $100\text{ g/l}$?**
*Round your answer, if necessary, to the nearest hundredth.*
[[☃ math-keypad 1]] hours