10 Famous Mathematical Puzzles in History - The Problems That Changed the Way We Think
Mathematics isn’t just about answers – it’s about the puzzles that make us think differently. For centuries, people have been drawn to the challenge of impossible questions, clever tricks, and logical riddles that test not just knowledge, but imagination. Some puzzles changed the course of mathematics; others became legends that still baffle us today.
Here are ten of the most famous mathematical puzzles in history – each one a reminder that the joy of maths often lies in the mystery.
1. The Riddle of the Sphinx (c. 2500 BCE)
The world’s oldest “logic puzzle” began as mythology. The Sphinx of Thebes asked travellers: “What walks on four legs in the morning, two legs at noon, and three in the evening?”
The answer – a human, who crawls as a baby, walks as an adult, and uses a stick in old age – reminds us that reasoning and pattern recognition are ancient skills, long before formal mathematics existed.
2. Archimedes’ Cattle Problem (3rd Century BCE)
Archimedes posed a puzzle involving the number of cattle in the Sun God’s herd – with conditions so complex that solving it requires equations with millions of digits.
It was one of the earliest examples of a Diophantine problem, where only whole-number solutions are allowed. It showed that maths can be both poetic and impossible.
3. The Seven Bridges of Königsberg (1736)
In the Prussian city of Königsberg, there were seven bridges linking parts of the city. Locals wondered if you could walk through the city crossing each bridge exactly once.
Leonhard Euler proved it couldn’t be done – and in doing so, invented graph theory, the foundation of modern network analysis used today in everything from map apps to social media.
4. The Monty Hall Problem (1975, based on earlier logic puzzles)
A game show host offers three doors – behind one is a car, behind two are goats. You pick one door, and the host opens another to show a goat. Should you switch your choice?
Most people think it doesn’t matter, but maths says otherwise: switching doubles your chances of winning (from 1/3 to 2/3). This puzzle became a classic study of probability and intuition.
5. The Towers of Hanoi (1883)
Invented by French mathematician Édouard Lucas, this puzzle uses three pegs and a stack of disks. The goal is to move the entire stack to another peg, one disk at a time, without placing a larger disk on a smaller one.
The solution requires a precise sequence – 2ⁿ − 1 moves for n disks – revealing the beauty of exponential growth and recursive thinking.
6. The Four Colour Map Problem (1852–1976)
Can every map be coloured using only four colours so that no two neighbouring regions share the same colour? For over a century, no one could prove it. Finally, in 1976, Kenneth Appel and Wolfgang Haken solved it using a computer – the first major theorem proven by technology.
It changed not only cartography but also how mathematicians viewed computers in proof-making.
7. The Magic Square of Lo Shu (Ancient China, c. 2200 BCE)
Legend says a turtle rose from the Luo River with a pattern of dots on its shell – the first magic square, where all rows, columns, and diagonals add to the same number (15).
It became a symbol of harmony and balance in Chinese culture and inspired centuries of fascination with numerical patterns.
8. The Königsberg Knight’s Tour (9th Century and beyond)
A version of this puzzle appears in medieval manuscripts: can a chess knight visit every square on a chessboard exactly once?
It became a classic example of combinatorial reasoning, connecting chess, logic, and pathfinding – ideas still used in robotics and algorithm design today.
9. Fermat’s Last Theorem (1637–1994)
Pierre de Fermat scribbled in the margin of a book that he had a “marvellous proof” for the statement xⁿ + yⁿ = zⁿ has no whole-number solutions for n > 2 – but the margin was too small to contain it.
It remained unsolved for over 350 years, until Andrew Wiles finally proved it in 1994 using advanced algebraic geometry. A puzzle born from curiosity became one of the greatest triumphs in mathematical history.
10. The Collatz Conjecture (1937 – Still Unsolved)
Start with any number. If it’s even, divide by 2. If it’s odd, multiply by 3 and add 1. Repeat the process. No matter what number you start with, you’ll eventually reach 1 – or will you?
No one knows for sure. The Collatz Conjecture is simple enough for children to play with, but deep enough to defy the world’s best mathematicians.















