There are several different arrangements for three people to take pictures continuously.

Three people lined up to take pictures, and there were six arrangements. This problem can also be solved by total permutation: a (3 3,3) = 3× 2×1= 6.

Photography relies on shops such as "video shops" to describe its appearance with traditional portrait methods. At that time, the painter was called "Xiao Zhao" and the deceased was painted as "image". After photography was introduced into China, people linked these two words together and called them "photography".