explanation : when a gas has volume V and pressure P, total translational kinetic energy of all molecules of gas is 3/2PV.
actually , Translational kinetic energy depends upon translational degree of freedom. and we know, there are only three degree of freedom in translational motion for any gas { monoatomic, diatomic or triatomic etc...}
Hence under same pressure, equal volumes of gaseous molecules have same translational kinetic energy i.e. (3/2)PV.