Are you smarter than a Singaporean ten-year-old?
Can you beat Sherlock Holmes?
If you think the answer is yes - I challenge you to solve my problems.
Here are 125 of the world's best brainteasers from the last two millennia, taking us from ancient China to medieval Europe, Victorian England to modern-day Japan, with stories of espionage, mathematical breakthroughs and puzzling rivalries along the way.
Pit your wits against logic puzzles and kinship riddles, pangrams and river-crossing conundrums. Some solutions rely on a touch of cunning, others call for creativity, others need mercilessly logical thought. Some can only be solved be 2 per cent of the population. All are guaranteed to sharpen your mind. Let's get puzzling!
Alex Bellos is brilliant on all things mathematical. He has a degree in Mathematics and Philosophy from Oxford University. His bestselling books Alex's Adventures in Numberland and Alex Through the Looking-Glass have been translated into more than 20 languages. He is the co-author of a mathematical colouring book, Snowflake, Seashell, Star, and he has launched an elliptical pool table, LOOP. He writes a popular maths blog and a puzzle blog for the Guardian. His next book, Puzzle Ninja, will be published in October 2017.