One gas of n_1 mole of molecules at temperature T_1, volume V_1, and pressure P_1, and another gas of n_2 mole of molecules at temperature T_2,…

One gas of $\displaystyle n_1$ mole of molecules at temperature $\displaystyle T_1$, volume $\displaystyle V_1$, and pressure $\displaystyle P_1$, and another gas of $\displaystyle n_2$ mole of molecules at temperature $\displaystyle T_2$, volume $\displaystyle V_2$, and pressure $\displaystyle P_2$, are mixed resulting in pressure $\displaystyle P$ and volume $\displaystyle V$ of the mixture. The temperature of the mixture is $\displaystyle \_\_\_\_$.