A slab of stone of area 0.36 m^2 and thickness 0.1 m is exposed on the lower surface to steam at 100^° C. A block of ice at 0^° C rests on the upper…

A slab of stone of area $\displaystyle 0.36 \mathrm{~m}^2$ and thickness $\displaystyle 0.1$ m is exposed on the lower surface to steam at $\displaystyle 100^{\circ} \mathrm{C}$. A block of ice at $\displaystyle 0^{\circ} \mathrm{C}$ rests on the upper surface of the slab. In one hour $\displaystyle 4.8$ kg of ice is melted. The thermal conductivity of slab is : (Given latent heat of fusion of ice $\displaystyle =3.36 \times 10^5 \mathrm{~J} \mathrm{~kg}^{-1}$) :