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 \( T_2 \), volume \( V_2 \) and pressure \( P_2 \), are mixed resulting in pressure \( P \) and volume \( V \) of the mixture. The temperature of the mixture is _______.
