Two converging lenses are placed 30.0cm apart. The focal length of the lens on the right is 20.0cm, and the focal length of the lens on the left is 15.0cm. An object is placed to the left of the 15.0-cm-focal-length lens. A final image from both lenses is inverted and located halfway between the two lenses. How far to the left of the 15.0-cm-focal-length lens is the original object?