Disc of radius a/2 is cut from disc of radius a. Find x-co-ordinate of COM from origin.

Question

Disc of radius $a\over2$ is cut from disc of radius a. Find x-co-ordinate of COM from origin.

(1) $5a\over6$

(2) $a\over6$

(3) $a\over3$

(4) $a\over2$