Heat And Thermodynamics

A flask contains argon and chlorine in the ratio of $2: 1$ by mass, the temperature of mixture is $27^{\circ} \mathrm{C}$, the ratio of root mean square ( $U_{\mathrm{rms}}$ ) of the molecule of two gases (Given, Atomic mass of argon $=39.9 v$, Molecular mass of chlorine $=70.9 u$ )