UPSC 2015 CDS I GK Paper

A man standing 1 m in front of a plane mirror approaches the mirror by 40 cm. It means now the man is standing 0.6 m in front of the mirror. For plane mirrors, the object distance is equal to the image distance, i.e., the image is the same distance behind the mirror as the object is in front of the mirror. If the man stands at a distance of 0.6 m from a plane mirror, then the man must focus at a location 0.6 metres behind the mirror in order to view his image.