Heat And Thermodynamics

A flask contains argon and chlorine in the ratio of $2: 1$ by mass. The temperature of the mixture is $27^{\circ} \mathrm{C}$. The ratio of root mean square speed of the molecules of the two gases $\left(\frac{V_{\mathrm{rms}}^{\mathrm{Ar}}}{V_{\mathrm{rms}}^{\mathrm{Cl}}}\right)$ is:

(Atomic mass of argon $=40.0 \mathrm{u}$ and molecular mass of chlorine $=70.0 \mathrm{u}$ )