Can a stationary object remain stationary if multiple external forces act upon it?

$A$ spherical ball of mass $m=5\,kg$ rests between two planes which make angles of $30^{\circ}$ and $45^{\circ}$ respectively with the horizontal. The system is in equilibrium. Find the normal forces exerted on the ball by each of the planes. The planes are smooth.

$A$ rod of weight $w$ is supported by two parallel knife edges $A$ and $B$ and is in equilibrium in a horizontal position. The knives are at a distance $d$ from each other. The centre of mass of the rod is at a distance $x$ from $A$.

As shown in the figure,the tension in the horizontal cord is $30 \, N$. The weight $W$ and the tension in the string $OA$ in Newton are:

$A$ metal sphere is hung by a string fixed to a wall. The sphere is pushed away from the wall by a stick. The forces acting on the sphere are shown in the second diagram. Which of the following statements is wrong?

Write the condition of equilibrium when three forces act on a particle.