Each year the Royal Statistical Society posts a "Christmas Quiz." The 2017 Christmas Quiz is here.
The embed above is a convenient image, but is not representative of the quiz as a whole, much of which is not "mathematical."
I've got questions 1b and 12 mostly done, and may work on some more as time permits, but I'm saving most of my energy for the pending release of the King William's College General Knowledge Quiz, which should be out any day now. Great fun and an immense challenge.
Related: Here's a good puzzle for you (with links to the 2016 RSS quiz - and answers).
Addendum: Answers to the 2017 RSS Christmas Quiz now in the Comments.
