Hi Zahid,

Let's assume that the distance of the man from the mirror is D. The image will be at a distance D behind the mirror. The distance between the man and the image is 2D.

After one second the man moves a distance of 5 m/s toward the mirror.

The image also moves a distance of 10 m/s toward the mirror.

Distance between the man and the image is (2D – 30)

In one second the distance between the man and image has reduced by an amount = 2D – (2D –30) = 30 m.

Thus the man’s speed toward the image is 30 m/s.