$A$ clock hung on a wall has marks instead of numbers on its dial. On the opposite wall there is a mirror,and the image of the clock in the mirror,if read,indicates the time as $8:20$. What is the actual time in the clock?

Two plane mirrors $A$ and $B$ are aligned parallel to each other,as shown in the figure. $A$ light ray is incident at an angle of $30^\circ$ at a point just inside one end of $A$. The plane of incidence coincides with the plane of the figure. The maximum number of times the ray undergoes reflections (including the first one) before it emerges out is

$A$ boy of height $1.5\, m$ with his eye level at $1.4\, m$ stands before a plane mirror of length $0.75\, m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8\, m$. Then:

The figure shows a cubical room $ABCD$ with the wall $CD$ as a plane mirror. Each side of the room is $3\,m$. $A$ camera is placed at the midpoint of the wall $AB$. At what distance should the camera be focused to photograph an object placed at $A$?

$A$ point source of light $S$ is placed in front of two large mirrors as shown. Which of the following observers will see only one image of $S$?

Find the velocity of the image with respect to the mirror.