Answer
The wedge-shaped door stopper should be placed as far from the hinges as possible.
Work Step by Step
The torque is proportional to the distance between the point where the force is applied and the axis of rotation. For a swinging door, the axis of rotation is at the hinges.
If the force from the wedge-shaped door stopper is applied near the hinges, then the distance between the applied force and the axis of rotation is small and the resulting torque will be small. If the same force from the door stopper is applied farther from the hinges, then the distance between the applied force and the axis of rotation is larger and the resulting torque will be larger, which makes it easier to hold the door open.
The wedge-shaped door stopper should be placed as far from the hinges as possible.
