ASU 364 All Soviet Union MO 1983 kindergarten children's no divisible by 8
Source:
July 28, 2019
number theorycombinatorics
Problem Statement
The kindergarten group is standing in the column of pairs. The number of boys equals the number of girls in each of the two columns. The number of mixed (boy and girl) pairs equals to the number of the rest pairs. Prove that the total number of children in the group is divisible by eight.