Water of mass $m_{2}$ = 1 kg is contained in a copper calorimeter of mass $m_{1}$ = 1 kg. Their common temperature t = $10_{0}C$. Now a piece of ice of mass $m_{3}$ = 2 kg and temperature is $−11_{0}C$ dropped into the calorimeter. Neglecting any heat loss, the final temperature of system is. [specific heat of copper = 0.1 Kcal/ kg$_{0}C$, specific heat of water = 1 Kcal/kg$_{0}C$, specific heat of ice = 0.5 Kcal/kg$_{0}C$, latent heat of fusion of ice = 78.7 Kcal/kg]