Intuition for COM

Q.

Four particles $A$, $B$, $C$ and $D$ having masses $m$, $2m$, $3m$ and $4m$ respectively are placed in order at the corners of a square of side $a$. Locate the centre of mass

1. None of these

2. $\frac{a}{2}$ , $\frac{a}{2}$

3. $\frac{a}{2}$, $\frac{7a}{10}$

4. $\frac{a}{2}$, $\frac{3}{4}$

Q. F is gravitational force between two bodies of equal mass M. Choose force for new masses at same distance.

1. $4F$
2. $2F$
3. $3F$
4. $M$ & $3M$
5. $2M$ & $2M$
6. $M$ & $2M$