I have always loved brain teasers and riddles ever since I was a little boy, and now that I am a teacher, I love giving these problems to my students and watching the way their brains scramble to try and find the answer – often students can surprise you when they’re pushed outside of their normal boundaries of thinking.
I have a few brain teasers I’d like to share with you all, but first I want to mention the neat little book from which I am finding them – Enigma, by Fabrice Mazza and Sylvain Lhullier (with illustrations by Ivan Sigg). I found this book on sale at a stall just outside a book shop, and I just couldn’t help myself – I had to have it, both for teaching and for myself!
It contains over 170 different puzzles (complete with solutions at the back), and the puzzles cover everything from brain teasers and riddles, to games of logic, word games and paradoxes. Each puzzle is on a separate page, most accompanied by illustrations which often demonstrate the problem. The pages are also stained a little, and decorated to create a sort of medieval feel to the whole thing, which personally I really like.
I’ll include a few of my favourite puzzles here – feel free to leave your guesses at any or all of the puzzles as a comment, and I shall reveal the answers later this week!
At a tournament, there is a tie between two knights. To decide between them, the king says to them: “See the tower rising over the horizon? The one whose horse arrives last at the tower will win the tournament.” With these words, both knights run to the stables, mount a horse and head straight towards the tower at a great gallop! How can we explain the knights’ illogical behaviour?
Godfrey of Bouillon has five children. Half are daughters. How can this be explained?
During a knights’ tournament, a man and his son are two of the candidates in the lists. The father is hit by a lance and he dies on the spot. His son, also wounded, is carried into a tent. The doctor in charge of examining him leans over the stretcher and exclaims “My God! It’s my son!” How is this possible?
Three travellers stop over at an inn, where they hire a room for 30 pennies a night. They each put in 10 pennies. Because the innkeeper likes them, he lowers the price to 25 pennies and gives them back 5 pennies. But there are three of them, so they take 1 penny each and leave the 2 pennies left over as a tip. So each of them has paid 9 pennies (3 x 9 = 27) and the innkeeper gets 2 pennies back. But 27 + 2 = 29. Where has the thirtieth penny gone?
How can you make 24, using each of the numbers 5, 5, 5 and 1 once? The only operations allowed are addition, subtraction, multiplication and division (but you can use brackets, too, to play around with the order of the operations).
Leave your guesses in the comments section, and feel free to ask brain teasers of your own if you know any good ones! And if you don’t want to accidentally find out the answer, be sure not to read comments from other people just in case they’ve cracked it!
Good luck, and have fun!