A negative unity feedback system has the loop transfer functions as

$G(s)=\frac{10}{s(s+10)}$

With a $2\%$ criterion, the settling time for the unit step closed loop response, is

a$.,t_s=0\mathrm{.}02$ secs$.$

b$.,t_s=0\mathrm{.}92$ secs$.$

c$.,t_s=0\mathrm{.}19secs.$