Safety First
On an average weekend, the emergency room at the John Radcliffe Hospital in Oxford treats 67 children for injuries sustained in accidents.
On two recent weekends, however — June 21, 2003, and July 16, 2005 — only 36 children needed treatment. Can you guess why?
Requiescat In Pace
A puzzle from 1796. “This curious inscription is humbly dedicated to the penetrating geniuses of Oxford, Cambridge, Eton, and the learned Society of Antiquaries.” Can you decipher it?
Highway Robbery
A stranger called at a shoe store and bought a pair of boots costing six dollars, in payment for which he tendered a twenty-dollar bill. The shoemaker could not change the note and accordingly sent his boy across the street to a tailor’s shop and procured small bills for it, from which he gave the customer his change of fourteen dollars. The stranger then disappeared, when it was discovered that the twenty-dollar note was counterfeit, and of course the shoemaker had to make it good to the tailor. Now the question is, how much did the shoemaker lose?
– H.E. Licks, Recreations in Mathematics, 1917
Connection Puzzle
Here’s a simplified version of a classic puzzle by Sam Loyd. Connect each square to its triangle with a line. The lines must stay within the boundary and may not cross one another.
Alcohol Problem
Fill one glass with wine and another with water. Transfer a teaspoonful of wine from the first glass into the second. Then transfer a teaspoonful of that mixture back into the first glass. Now, is there more wine in the water or water in the wine?
Most people will predict it’s the former, but in fact the two quantities will always be the same. Can you see why?
One-Sided States
Only two U.S. state names can be typed with a single hand on a normal keyboard. What are they?
A Weighty Problem
“Here is a quaintly told problem in mechanics, which, despite its apparent simplicity, is said to have caused Lewis Carroll considerable disquietude,” writes Sam Loyd in his Cyclopedia of 5000 Puzzles, Tricks, and Conundrums (1914). He quotes Carroll:
If, to a rope, passed over a loose pulley, is suspended a ten-pound counter weight, which balances exactly with a monkey eating an apple, swinging at the other end, what would be the result if the monkey attempts to climb the rope?
“It is very curious to note the different views taken by good mathematicians,” Carroll noted. “Price says the weight goes up with increasing velocity. Both Clifton and Harcourt maintain that the weight goes up at the same rate of speed as the monkey; while Sampson says that it goes down.”
So which is it? Be warned, Loyd’s thinking is inconclusive.
Problem Solved
What happens when an irresistible force meets an immovable object?
It can’t happen. If a force is irresistible, then by definition there’s no such thing as an immovable object (and vice versa).
Zebra Puzzle
This puzzle has been attributed both to Lewis Carroll and to Albert Einstein:
- There are five houses in a row. Each of the houses is painted a different color, and their occupants come from different countries, own different pets, drink different beverages, and smoke different cigarette brands.
- The Englishman lives in the red house.
- The Spaniard owns the dog.
- Coffee is drunk in the green house.
- The Ukrainian drinks tea.
- The green house is immediately to the right (your right) of the ivory house.
- The Old Gold smoker owns snails.
- Kools are smoked in the yellow house.
- Milk is drunk in the middle house.
- The Norwegian lives in the first house.
- The man who smokes Chesterfields lives in the house next to the man with the fox.
- Kools are smoked in the house next to the house where the horse is kept.
- The Lucky Strike smoker drinks orange juice.
- The Japanese smokes Parliaments.
- The Norwegian lives next to the blue house.
Who drinks water? Who owns the zebra?
Diophantus’ Age
No one knows much about Diophantus, the Greek mathematician, but in the sixth century a math puzzle purported to give his epitaph:
“This tomb holds Diophantus. Ah, what a marvel! And the tomb tells scientifically the measure of his life. God vouchsafed that he should be a boy for the sixth part of his life; when a twelfth was added, his cheeks acquired a beard; He kindled for him the light of marriage after a seventh, and in the fifth year after his marriage He granted him a son. Alas! late-begotten and miserable child, when he had reached the measure of half his father’s [total] life, the chill grave took him. After consoling his grief by this science of numbers for four years, he reached the end of his life.”
At what age did he die?
Unwanted
The maker doesn’t need it.
The buyer doesn’t use it.
The user doesn’t know he’s using it.
What is it?
The Kayaker
A child releases a toy boat in a stream that flows at 3 miles an hour. At that instant, a kayaker 14 miles downstream begins paddling upstream at 7 miles per hour. How long will it take him to reach the toy?
Missing Square Puzzle
New York magician Paul Curry invented this puzzle in 1953. When the pieces of the triangle are rearranged as shown, suddenly a square is missing. How is this possible?
Cryptarithm
A “cryptarithm,” originally published by Henry Dudeney in the July 1924 Strand:
Each letter stands for a different digit. Can you identify them?
The Poe Cryptographic Challenge
Edgar Allan Poe was fascinated by cryptograms. He once offered a free magazine subscription to any reader who could stump him, and he claimed to have solved all 100 ciphers that were sent in.
That mania ultimately created a mystery that lasted 150 years after the writer’s death. In 1840 Poe published two ciphers sent in by a “Mr. W.B. Tyler” and challenged readers to solve them. No readers succeeded, and in fact the first cipher wasn’t cracked until 1992, when University of Illinois English professor Terence Whalen decoded a passage from Joseph Addison’s 1713 play Cato.
The second puzzle was even harder, a polyalphabetic substitution cipher using several different symbols for each English letter — and containing several mistakes. It was finally solved in 2000 by Toronto software engineer Gil Broza:
It was early spring, warm and sultry glowed the afternoon. The very breezes seemed to share the delicious langour of universal nature, are laden the various and mingled perfumes of the rose and the –essaerne (?), the woodbine and its wildflower. They slowly wafted their fragrant offering to the open window where sat the lovers. The ardent sun shoot fell upon her blushing face and its gentle beauty was more like the creation of romance or the fair inspiration of a dream than the actual reality on earth. Tenderly her lover gazed upon her as the clusterous ringlets were edged (?) by amorous and sportive zephyrs and when he perceived (?) the rude intrusion of the sunlight he sprang to draw the curtain but softly she stayed him. “No, no, dear Charles,” she softly said, “much rather you’ld I have a little sun than no air at all.”
Probably it’s a quote from a novel of the time.
Interestingly, some scholars think Poe himself composed the ciphers, as city directories show no W.B. Tyler in that period. We’ll never know for sure, but Poe himself once wrote:
Ye who read are still among the living; but I who write shall have long since gone my way into the region of shadows. For indeed strange things shall happen, and secret things be known, and many centuries shall pass away, ere these memorials be seen of men. And, when seen, there will be some to disbelieve, and some to doubt, and yet a few who will find much to ponder upon in the characters here graven with a stylus of iron.
The Monty Hall Problem
Suppose you’re a contestant on Let’s Make a Deal. Monty Hall shows you three doors. One hides a sports car; the other two hide goats. You choose Door #1.
Before opening Door #1, though, Monty opens Door #3, revealing a goat. Now you can stick with Door #1 or switch to Door #2. Which should you do?
Hotel Puzzle
Three men stop at a hotel and agree to share a room for $30. Each gives the desk clerk $10.
Later, the clerk realizes he’s overcharged them for the room by $5. He gives the bellboy five $1 bills and tells him to return the money to the three men. The unscrupulous bellboy keeps $2 for himself and gives $1 to each of the three men.
So the men paid $9 each for the room, for a total of $27. The bellboy has $2. What happened to the other dollar?
No Tips Either Way
Okay, you’re a chef. Which of these trays was requested for a singer’s dressing room, and which is the last meal of a Texas death-row inmate?
A. Neil Diamond (“Love on the Rocks”)
B. Nelly (“Hot in Herre”)
C. Smokey Robinson (“Tears of a Clown”)
D. B.B. King (“The Thrill Is Gone”)
E. Cornelius Goss (beat a Dallas homeowner to death with a board)
F. Gerald Mitchell (shotgunned two customers during a Houston drug deal)
G. James Collier (shot two Wichita Falls residents while stalking his daughter)
H. James Powell (raped and murdered a 10-year-old in Beaumont)
I. Paul Nuncio (strangled a 61-year-old in Plainview)
1. BBQ chicken wings, chips, fruit, ginger ale
2. 1 apple, 1 orange, 1 banana, coconut, peaches
3. One pot of coffee
4. Enchiladas, burritos, chocolate ice cream, cantaloupe (whole, split in half)
5. Chinese takeout, coffee
6. 1 bag of assorted Jolly Ranchers
7. Baked salmon, french fries, fruit platter, salad, soda
8. Nothing
9. Thirty jumbo shrimp, cocktail sauce, baked potato, French fries, ketchup, butter, one T-bone steak, one chocolate malt, one gallon of vanilla ice cream, and three cans of Big Red
What’s Odd?
How quickly can you find out what is unusual about this paragraph? It looks so ordinary that you would think that nothing was wrong with it at all and, in fact, nothing is. But it is unusual. Why? If you study it and think about it you may find out, but I am not going to assist you in any way. You must do it without coaching. No doubt, if you work at it for long, it will dawn on you. Who knows? Go to work and try your skill. Par is about half an hour.
Trick Mules Puzzle
Sam Loyd was only 17 when his “Trick Mules Puzzle” swept the country in 1858. He finally sold it to P.T. Barnum for $10,000.
Print this page and cut out the three pieces along the dashed lines. Now arrange them so that it looks like each jockey is riding a mule. You may overlap the pieces, but you mustn’t fold them.
It’s harder than it looks.
Puzzling Brothers
Tom and Dick were born on the same day of the same year to same mother and father. They look almost exactly alike, yet they are not twins. How can this be?
The Underpass
A large truck had become wedged under an underpass. The driver couldn’t move it backward or forward, and traffic was beginning to back up behind it.
He was on the point of desperation when a little boy approached him and offered a suggestion. A few minutes later the truck was on its way. What did the boy tell the driver?
