I have n friends. Every night of the 365-day year I invite three of them to dinner. What is the smallest n could be such that it is still possible for me to make these invitations without ever inviting the same group of three friends? (I can invite the same friend, or even the same pair of friends, but never the same whole group of three.)
is this from aops because i just saw this problem in one of the aops videos they provide in homework