MathDB
Trivial double counting- graph edition

Source: 4th Memorial Mathematical Competition "Aleksandar Blazhevski - Cane"- Junior D2 P6/ Senior D2 P5

December 21, 2022
combinatoricsgraph theorydouble countingtriplets

Problem Statement

There are 10001000 students in a school. Every student has exactly 44 friends. A group of three students {A,B,C} \left \{A,B,C \right \} is said to be a friendly triplet if any two students in the group are friends. Determine the maximal possible number of friendly triplets.
Proposed by Nikola Velov