Hi ,

We have,


X coordinate = MX + MX / M + M
= (100 x 2) + (300 x -6) / 100 + 300
= 200 - 1800 / 400
= -1600 / 400
= -4


Y coordinate = MY + MY / M + M
= (100 x 5) + (300 x 4) / 400
= 500 + 1200 / 400
= 1700 / 400
= 4.25


Z coordinate= MZ + MZ / M + M
= (100 x 13) + (300 x -2) / 400
= 1300 - 600 / 400
= 700 / 400
= 1.75


Thus, position of Centre of Mass is
X=-4,
Y=4.25,
Z=1.75

I hope that this helps you

Thankyou