A $62\mathrm{.}5k{m}^2$ catchment area received precipitation of $25\mathrm{.}4mm$ in one week. The infiltration loss is estimated as $6\mathrm{.}8mm$ for the same week. Neglecting the evapotranspiration losses, determine the average runoff reached to the outlet of catchment in $\frac{m^3}{s}.($Answer: $1\mathrm{.}92($:$\frac{m^3}{s}$