Three perfect gases at absolute temperatures $T_{1}, T_{2}$ and $T_{3}$ are mixed. The masses of molecules are $m_{1}, m_{2}$ and $m_{3}$ and the number of molecules are $n_{1}, n_{2}$ and $n_{3}$ respectively. Assuming no loss of energy, the final temperature of the mixture is: (1) $\frac{n_{1}T_{1}+n_{2}T_{2}+n_{3}T_{3}}{n_{1}+n_{2}+n_{3}}$ (2) $\frac{n_{1}T_{1}+n_{2}T_{2}^{2}+n_{3}T_{3}^{2}}{n_{1}T_{1}+n_{2}T_{2}+n_{3}T_{3}}$ (3) $\frac{n_{1}^{2}T_{1}^{2}+n_{2}^{2}T_{2}^{2}+n_{3}^{2}T_{3}^{2}}{n_{1}T_{1}+n_{2}T_{2}+n_{3}T_{3}}$ (4) $\frac{\left(T_{1}+T_{2}+T_{3}\right)}{3}$
Three perfect gases at absolute temperatures $T_{1}, T_{2}$ and $T_{3}$ are mixed. The masses of molecules are $m_{1}, m_{2}$ and $m_{3}$ and the number of molecules are $n_{1}, n_{2}$ and $n_{3}$ respectively. Assuming no loss of energy, the final temperature of the mixture is:\\
(1) $\frac{n_{1}T_{1}+n_{2}T_{2}+n_{3}T_{3}}{n_{1}+n_{2}+n_{3}}$\\
(2) $\frac{n_{1}T_{1}+n_{2}T_{2}^{2}+n_{3}T_{3}^{2}}{n_{1}T_{1}+n_{2}T_{2}+n_{3}T_{3}}$\\
(3) $\frac{n_{1}^{2}T_{1}^{2}+n_{2}^{2}T_{2}^{2}+n_{3}^{2}T_{3}^{2}}{n_{1}T_{1}+n_{2}T_{2}+n_{3}T_{3}}$\\
(4) $\frac{\left(T_{1}+T_{2}+T_{3}\right)}{3}$