\textbf{74 --} $80\,\text{g}$ of water at $25^\circ\text{C}$ together with $20\,\text{g}$ of water at $80^\circ\text{C}$ are poured into a metal container of mass $300\,\text{g}$ at $32^\circ\text{C}$. What is the equilibrium temperature in degrees Celsius? ($c_{\text{metal}} = 400\,\dfrac{\text{J}}{\text{kg.K}}$ and $c_{\text{water}} = 4200\,\dfrac{\text{J}}{\text{kg.K}}$)
$$50 \;(1) \qquad 42 \;(2) \qquad 40 \;(3) \qquad 32 \;(4)$$