Question 6
There are $2022$ users on Mathbook. Friendship is mutual and permanent. A new friendship may be formed only between users who have at least two friends in common. What is the minimum number of existing friendships that permits everyone eventually to become friends with everyone else?
Proposed by Yannick Yao. Source: Evan Chen’s third-party solution notes; https://aops.com/community/p24774626. One point is a nonofficial editorial normalization; this essay requires manual grading.
Proposed by Yannick Yao. Source: Evan Chen’s third-party solution notes; https://aops.com/community/p24774626. One point is a nonofficial editorial normalization; this essay requires manual grading.