Three forces are acting on a body to make it in equilibrium , which set can not do it ?

Three forces vecA=(hati+hatj+hatk),vecB=(2hati-hatj+3hatk) and vecC acting on a body to keep it in equilibrium. Then vecC is

If the sum of all the forces acting on a body is zero, is it necessarily in equilibrium ? If the sum of all the forces on a particle is zero, is it necessarily in equilibrium?

Assertion : A body subjected to three concurrent forces cannot be in equilibrium. Reason : If large number of concurrent forces acting on the same point, then the point will be in equilibrium, if sum of all the forces is equal to zero.

(A) : A body subjected to three concurrent forces cannot be in equilibrium. (R) : If large number of concurrent forces acting on the same point, then the point may be in equilibrium, even if the vectorial sum of all the force is not zero.

(A) : A body subjected to three concurrent forces cannot be in equilibrium. (R) : If large number of concurrent forces acting on the same point, then the point may be in equilibrium, even if the vectorial sum of all the force is not zero.

A body is said to be in equilibrium if all the forces acting on it