Two point-like objects of masses $20 \mathrm{gm}$ and $30 \mathrm{gm}$ are fixed at the two ends of a rigid massless rod of length $10 \mathrm{cm}$. This system is suspended vertically from a rigid ceiling using a thin wire attached to its center of mass, as shown in the figure. The resulting torsional pendulum undergoes small oscillations. The torsional constant of the wire is $1.2\times {10}^{-8} \mathrm{N} \mathrm{m} {\mathrm{rad}}^{-1}$. The angular frequency of the oscillations in $n\times {10}^{-3} \mathrm{rad} {\mathrm{s}}^{-1}$. The value of $n$ is _____.

Hence, the correct answer is 10.