In the figure shown a hole of radius 2 cm is made in a semicircular disc of radius `6pi` at a distance 8 cm from the centre C of the disc. The distance of the centre of mass of this system from point C is :

A circular hole of radius r is made in a disk of radius R and of uniform thickness at a distance a from the centre of the disk. The distance of the new centre of mass from the original centre of mass is

A circular hole is cut from a disc of radius 6 cm in such a way that the radius of the hole is 1 cm and the centre of 3 cm from the centre of the disc. The distance of the centre of mass of the remaining part from the centre of the original disc is

A circular hole is cut from a disc of radius 6 cm in such a way that the radius of the hole is 1 cm and the centre of 3 cm from the centre of the disc. The distance of the centre of mass of the remaining part from the centre of the original disc is