50 g of ice at 0 °C is dropped into 200 g of water at 40 °C in a container of negligible heat capacity, with no heat lost to the surroundings. Take the specific heat of water as 4200 J kg⁻¹ K⁻¹ and the latent heat of fusion of ice as 3.36 × 10⁵ J kg⁻¹. The final temperature of the mixture is