At what angle (in degrees) should two plane mirrors be inclined to obtain $3$ images?

The coordinates of the image with respect to the origin $c$ will be

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

$A$ small object is placed $10\, cm$ in front of a plane mirror. If you stand behind the object $30\, cm$ from the mirror and look at its image,the distance focused for your eye will be........$cm$.

$A$ long horizontal mirror is next to a vertical screen (see figure). Parallel light rays are falling on the mirror at an angle $\alpha$ from the vertical. If a vertical object of height $h$ is kept on the mirror at a distance $d$ from the screen,where $d > h \tan \alpha$,the length of the shadow of the object on the screen would be

$A$ ray is reflected in turn by three plane mirrors mutually at right angles to each other. The angle between the incident and the reflected rays is......$^o$