The walls of an ice chest are made of 2.00 cm thick styrofoam with a thermal conductivity 0.0300 W/m?K. The total surface area of the ice chest is 1.20 m2. If 4.00 kg of ice at 0.00°C are placed in the chest and the temperature outside the chest is 20.0°C, how long does it take the ice to melt? Remember that the latent heat of fusion of water is 79.6 cal/g.