TCE is biodegrading in a treatment pond following first$-$order kinetics with a rate constant of

$0\mathrm{.}14$ day ${?}^{-1}.$ If the initial concentration of TCE is $175u\frac{g}{L},$ how long would it take for the

concentration to decrease to the drinking water standard of $5u\frac{g}{L}?$ Assume there is no flow

into or out of the pond.