Some 3 to 4 years ago, a math teacher at a Japanese primary school in Okazaki city, Aichi prefecture caused a nationwide uproar when he asked the following question to his 3rd graders on parent-visiting day:
If you have 18 friends, and you kill 3 of them each day, how many days would it take for you to kill them all?
He must’ve been a fan of Beat Takeshi’s Battle Royale.
6 days!