Q22. Three balls of masses $2 \mathrm {~kg} , 4 \mathrm {~kg}$ and 6 kg respectively are arranged at centre of the edges of an equilateral triangle of side 2 m . The moment of intertia of the system about an axis through the centroid and perpendicular to the plane of triangle, will be $\_\_\_\_$ $\mathrm { kgm } ^ { 2 }$.