For the last quarter-century, the Royal Statistical Society has published a fiendishly difficult Christmas quiz to entertain puzzle fans over the festive break - and this year’s special 25th Anniversary Edition, devised by Dr Tim Paulden, is sure to get the cogs spinning after a glass or two of mulled wine.
Cracking the fifteen problems below will require a potent mix of general knowledge, logic, and lateral thinking - but, as usual, no specialist mathematical knowledge is needed.
Two important tips for budding solvers:
Prizes of £150 (for the winner) and £50 (for the runner-up) in Wiley book vouchers will be awarded to the two highest-scoring entries. The winner will also receive a copy of Borel, a new stats-related board game. In addition, to mark the 25th Anniversary of the Christmas Quiz, the quizmaster will be making a donation of £250 to charity, to be split equally between good causes selected by the ten highest-scoring entries (whether received via StatsLife or the Guardian).
Entries from both individuals and teams are welcomed, but please note that a team will only be eligible to win a prize if it comprises five people or fewer, and includes at least two RSS members. The quizmaster's decision is final, and in the event of a tie, the prize-winners will be selected at random from the highest-scoring entries.
Q1. GREETINGS [9 points]
Each of the five strings below gives the initial letters of a quote or lyric with a festive flavour - however, each one contains three deliberate errors. Can you decipher them?
What song is represented by the fifteen errors, taken in order - and why is this a particularly apt choice?
Q2. BILKO [11 points]
Identify the following individuals, all of whom have something in common. Which two of them have previously collaborated, and in what context?
(a) The younger half of Tom & Jerry
(b) Lieutenant who played a colonel (and Ben, three times)
(c) Creator of a heavenly work that appears in a wintry tale (2018)
(d) Portrayer of Mrs White, whose two names share the same double letter
(e) "Numéro sept", who won gold, silver and bronze in summer 2018
(f) Served as #45, four after Nelson
(g) Christian vocalist born in a major city (where Holly is 18)
(h) SBC's satirical "hip-hop journalist", rarely seen without yellow-tinted shades
Q3. TOM, DICK, AND… [7 points]
Time to blow off some steam - whose name is encoded below, and what's the significance of the question title?
Which closely related individual produced works with names corresponding to these symbols - and how would this person's first name be encoded?
Q4. FLIP THE QUESTION [7 points]
(a) If the following all played together, which would be the odd one out - and why?
- KC & The Sunshine Band
- Tom Odell
- Dave Edmunds
(b) Loosely speaking, what might result from a collaboration between the following acts, in sequence? Emery; Earth, Wind & Fire; Fleetwood Mac; Positively Black; Snow Patrol; Lethal Bizzle; Elvis Presley; Bob Marley & The Wailers; The Beatles; The Sutherland Brothers; Simon Webbe; Foo Fighters; Martina McBride; The All-American Rejects; Drake
Q5. LOUD AND CLEAR [5 points]
Since 1975, what feat has been accomplished only by the following, plus one other person?
JE, GJ, GG, JE, DR, DC, VD, JT, AK, AK, MC, AK, NB, DG, AD
Who's missing, and what festive message is spelled out (twice) when they are added to the list?
Q6. FREEZE-FRAMES [10 points]
Each of the images below is a stylised snippet from a historical piece of art. In each case, identify the surname of the original artist. Whose name is revealed by the nine answers?
Q7. LOTS ON THEIR PLATE [5 points]
(a) In what context would juxtaposing a horse, a revolutionary, a language and a chihuahua produce a festive name? (Hint: 80% of Q2.)
(b) Chantal joins A to B, and adds C. Isala joins A to itself (around the outside), and adds D. Chantal joins B to C, and adds E. Isala joins B to E (on the inside), adds F, and smiles. What's going on - and where?
Q8. THREE POINT FIVE POINT... [3 points]
During 2018, three very short phrases - derived from comic strips published in January 1973, March 1972 and January 1960 - have been seen regularly by thousands of statisticians around the world. What are the phrases, and where have they appeared?
Q9. SPSS: A SPECIAL ANNIVERSARY [5 points]
If the nine numbers on the exterior are 50, 35, 27, 19, 24, 42, 37, 33 and 29, which twelve numbers appear in the interior? (A very appropriate property is shared by the largest interior number and three of its neighbours.)
Q10. BICHHOO (YO!) [8 points]
Which five English words should appear on the right-hand side of the equations below?
What festive message (echoing an earlier question) is encoded within the above image?
Finally, why might the question title strike a chord with somebody mentioned earlier in the quiz, based on their recent work - and in which other question would this person also feel particularly at home?
Q11. P.I.G. [5 points]
The first 25 elements of a certain sequence comprise seven 'd's, five 'e's, one 'f', five 'n's, six 's's, and one 'z' (in some order). What is the composition of the next 25 elements?
(The fifth element - the shortest in the sequence - might provide a little help.)
Q12. IT'S A LAP [6 points]
Professor Sandra Klaus, head of the Lapland School of Mathematics, rode into work on a moonlit Christmas Eve to find that someone had pinned 28 strands of tinsel to her blackboard in a curious configuration (see diagram below).
She observed that tinsel strands of the same colour always had the same length, while strands of different colours always had different lengths. Moreover, each colour appeared a distinct number of times: there was one purple strand, two blue strands, three orange strands, and so on.
Professor Klaus wondered whether this information was sufficient to calculate exactly the ratio of the longest strand length to the shortest strand length. Can you help her out?
Q13. FUSION [8 points]
(a) Fill in the question marks below:
The first member of the final pair is linked (in two different ways) to the theme of an earlier question - can you explain how?
(b) In a related vein, fill in the blank below:
Q14. HEX 19 [6 points]
Nathaniel lives on a small island. One weekend, after a barbecue, he decides to go for a random stroll, starting from his home hex (shown in red). On each 'step' of the stroll, Nathaniel randomly selects the next hex to visit from those adjacent to his current hex, with each option being equally likely. (Any adjacent hex may be chosen - even one he has previously visited.) If Nathaniel's stroll lasts for a total of 19 steps, what is his most likely final location?
Q15. THE BROMPTONS [5 points]
Devising unusual advent calendars for friends and family is a long-standing November tradition in the Brompton household, with a prize being awarded for the most intriguing design. This year's winner, announced at breakfast on 1 December, was youngest son Philip, who came up with the calendar pictured below. What is so special about it?