Solving serious puzzles — to catch criminals and thwart terrorist plots — is what the men and women who work at GCHQ do round the clock. It’s hardly surprising that many of them enjoy setting and solving them in their own time, too, pitting their wits against each other. This selection is from The GCHQ Puzzle Book (Penguin), put together by GCHQ’s spies, containing a Christmas puzzle challenge, too, and raising money for the Duke and Duchess of Cambridge’s Heads Together mental health campaign.
1. A round of drinks
What could follow Mojito, Eggnog, Riesling, Lemonade, Ouzo… ?
2. Composing a sequence
What is the final entry in this sequence?
Brahms’s 1st, Elgar’s 1st, Mahler’s 5th, Schubert’s 8th, Schumann’s 3rd, Borodin’s 2nd, Shostakovitch’s 9th, Bruckner’s 7th, Beethoven’s …?
3. Find N
In the following, ‘N’ sometimes represents two words. What are they?
N is W of S
S is N of E
E is E of N
W is W of E
M lives in Q, and is very fond of G. He is married to J, and they have two children, C and V. What do the children call M?
Whose works include:
a) OT, ACC, TOCS, ATOTC
b) ASIS, TSOF, THOTB, TVOF
c) S, VB, DAF, AHOD
6. A question to put you to sleep
Find a whole number which when spelled out has its letters in alphabetical order.
7. Age-old question
In 2011, members of the Riemann family were aged 11, 13, 41 and 47. Which year will be the next to be quite so special for them?
8. The list
What completes the list?
SORE, KEEL, COSH MARK
9. What connects?
Stewart Chail, Richard Heskit, Will Manby, Janis Borne, Jake McRigg