• Brainly User
Choose x-y -z axes let centre of mass of 8 cube be O as origin
let the center of mass of each cube be (l/2,l/2.l/2)(l/2,-l/2.l/2)(l/2,l/2.-l/2)(l/2,-l/2.-l/2)(-l/2,-l/2.l/2)(-l/2,l/2.-l/2)(-l/2,-l/2.-l/2)and (-l/2,l/2.l/2)
there center of mass is (0,0,0)
if any one cube is removed then the center of mass can be
then only 7 cubes should be there
so as centers are at length l/2 the distance according to given choice
must be c)