A process is described by the following first order transfer function:

$G(s)=Y\frac{s}{U}(s)=\frac{2e^{-s}}{3s+1}$

For a step input of magnitude $3$ for $u,$ determine the long$-$time $($steady state$)$ response of $y(y_{ss}).$ If the time constant and time delay are in seconds, how much time will it take for the response to reach $75\%$ of the steady state value?