12. David is observing his image in a plane mirror. The distance between the mirror and his image is 4 m. If he moves 1 m towards the mirror, then the distance between David and his image will be:
(i) 3 m (ii) 5 m (iii) 6 m (iv) 8 m
We are given the distance between the mirror and his image = 4 m
Now, if David moves 1 m towards the mirror, then the distance is = 4 − 1 = 3 m
Hence, the distance between David and his image is = 3 + 3 = 6 m.
Hence, the correct answer is option (iii).