In terms of newtons 3rd law of motion desribe this picture. newton's third law  is: for every action, there is an equal and opposite reaction.

Newton's third law (for every action, there is an equal and opposite reaction) means that in every interaction (in this case, that of the objects in the image), there is a pair of forces acting on the two interacting objects. When you sit on a chair, your body exerts a downward force on the chair and the chair exerts an upward force on your body. There are two forces resulting from this interaction - a force on the chair and a force on your body. This is embodied in the image by the two objects exerting force on each other (indicated by the arrows).

Hope this helps.

The answer is 323 g.