2 Kg of ice at -20 degree C is mixed with 5Kg of water 20 degree C in an insulating vessel containing negligible heat capacity. Measure the final mass of water remaining in the container. It is given that the specific heats of water and ice are 1Kcal/kg/degree C and 0.5Kcal/kg/degree C whereas latent heat of fusion of ice is 80 kcal/kg