Consider the following optical system consisting of a thin lens of focal length | f | = 4 0 cm , of a piece of glass whose curved face has a radius of curvature | R | = 2 5 cm and a concave mirror with a radius of curvature of 3 0 cm . Calculate the characteristics ( position , nature and magnification ) of the image of an object located to the left of the thin lens throughout the system. We give that a = 2 0 cm , b = 2 8 cm , c = 3 cm and d = 2 0 5 cm