Water flows from $\mathrm{P}$ to $\mathrm{Q}$ through two soil samples, Soil 1 and Soil $2,$ having cross sectional area of $80 \mathrm{~cm}^{2}$ as shown in the figure. Over a period of 15 minutes, $200 \mathrm{ml}$ of water was observed to pass through any cross section. The flow conditions can be assumed to be steady state. If the coefficient of permeability of Soil 1 is $0.02 \mathrm{~mm} / \mathrm{s},$ the coefficient of permeability of Soil 2 (expressed in $\mathrm{mm} / \mathrm{s}$ ) would be
Water flows from $\mathrm{P}$ to $\mathrm{Q}$ through two soil samples, Soil 1 and Soil $2,$ having cross sectional area of $80 \mathrm{~cm}^{2}$ as shown in the figure. Over a period of 15 minutes, $200 \mathrm{ml}$ of water was observed to pass through any cross section. The flow conditions can be assumed to be steady state. If the coefficient of permeability of Soil 1 is $0.02 \mathrm{~mm} / \mathrm{s},$ the coefficient of permeability of Soil 2 (expressed in $\mathrm{mm} / \mathrm{s}$ ) would be