An ice chest is constructed of 0.4 mm thick plain-carbon steel plate, a 1.9 cm thick layer of styrofoam {k=0.033 W/(m *C)} and a 0.65 cm thick fiber glass liner. The cooler has inside dimensions of 25*40*100 cm. The outside of the chest is exposed to air at 25 C with h=10 W/(m2*C). If the chest is completely filled with ice, calculate the time for the ice to completely melt. The heat of fusion for water is 330 kJ/kg.