Two adjacent walls and the ceiling of a rectangular room are mirror surfaced. The number of images of himself that an observer sees is:

The number of images formed if two plane mirrors are kept at an angle θ is given by,
and it is given by
For θ = 90°, number of images is
as is an even number.
So, 3 images will be formed for each perpendicular mirror pair. Thus, 6 images will be formed, 3 for adjacent walls and 3 for wall and ceiling mirrors.

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