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).
Puzzles
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?