A converging lens L1 of focal length 10cm is placed at a distance, y, in front of a diverging lens L2 of focal length 20cm. An illuminated object is placed at a distance of 20 cm in front of L1 and the final image by L2 formed at the principal focus of L2. Calculate the Final magnification. a) 4 b) 3.5 c) 3 d) 2.5 e) 2