Q. An object of height 8 cm is placed in front of a lens. It's inverted image of height 4.8 cm is formed on the screen. If the focal length of the lens is 12 cm then by drawing at scale calculate the object distance, image distance and magnification.
Taking scale as 1cm = 4cm I've drawn the principal axis and the lens and marked focus (F) at 3cm from the lens. But how do I proceed from here with only the heights of the object and image?!