An object is placed to the left of a lens, and a real image is formed to

Question:

An object is placed to the left of a lens, and a real image is formed to the right of the lens. The image is inverted relative to the object and is one-half the size of the object. The distance between the object and the image is 90.0 cm.
(a) How far from the lens is the object?
(b) What is the focal length of the lens?