For fans of outlandishly devious puzzles, the highlight of every Christmas is the RSS Quiz. No statistical knowledge is needed, but you will need all of your lateral thinking skills, extreme Google-fu and inspired leaps of pure intuition (these will form a set of what mathematicians call ‘necessary but not sufficient conditions’). You can’t win a prize if you’re not a member of the society, but since the questions are so preposterously difficult, this is unlikely to have a material effect.

Update: as RSS quizmaster Tim Paulden has pointed out in the comments, this year’s quiz has also been published by The Guardian, where there is a prize available to non-RSS-member teams.

This post is part of the Aperiodical’s 2018 Aperiodvent Calendar.