$2 \text{kg}$ of ice at $-{20}^{°}\text{C}$  is mixed with $5 \text{kg}$ of water at ${20}^{°}\text{C}$ . The water content in the final mixture is (Latent heat of ice $=80\text{kcal}/\text{kg}$ , specific heat of water $=1{{\text{kcalkg}}^{-1}}^{°}{\text{C}}^{-1}$ specific heat of ice  $=0.5{{\text{kcalkg}}^{-1}}^{°}{\text{C}}^{-1}$)