Category Archives: Uncategorized

The successor of the sultan (4)


The sultan asked the vizier:
“The tests so far for finding my successor are way too easy. We’ve got to make them harder. There are still dozens of candidates left.”
“This one is definitely more difficult. First, they got to swim”
“So they had in the previous test,” the sultan grumbled.
“If they come up to breath, there heads will be shot off,” the vizier explained. The sultan nodded approval.
“There are four doors.”
“So had the previous test”
“But now there are two labels on every door. So they’ve got to think twice as fast!”

Test 4***/*****

The first candidate look at the four doors.
“Again only one door hides a treasure,” the vizier explained. “There is a shark behind each of the other three.”
The candidate looked at the labels. He could see that there were two labels on each door, but he couldn’t read them.
“And how many labels are true? Or how many doors have true labels?”
“That is a very good question”, the sultan smiled. “As a matter of fact, knowing which door hides the treasure, it was impossible to decide upon the number of true labels. So how you should decide the number of true labels while you don’t know which door hides the treasure, is beyond me.”

Which door should the candidate open?


New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solution here.

Bongard problem rule 9


In 1967 the Russian scientist M.M. Bongard published a book containing 100 problems. Each problem consists of 12 small boxes: six boxes on the left and six on the right. Each of the six boxes on the left conforms to a certain rule. Each box on the right contradicts this rule. Your task, of course, is to figure out the rule.

A Bongard problem consists of two groups of 6 images. Each and every of the six images on the left complies wit a certain rule. Each of the 6 images on the right does NOT comply with this rule.

Rule 9**/*****

New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solutions here.

Lyfoes


New puzzle types are often an variation on an existing theme or situation.

Take for example the Towers of Hanoi. Citing wikipedia: It consists of three rods and a number of disks of different sizes, which can slide onto any rod. The puzzle starts with the disks in a neat stack in ascending order of size on one rod, the smallest at the top, thus making a conical shape.

The objective of the puzzle is to move the entire stack to another rod, obeying the following simple rules:
* Only one disk can be moved at a time.
* Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack or on an empty rod.
* No larger disk may be placed on top of a smaller disk.

A new variation on this puzzle is Lyfoes. The stacks have been replaced with tubes, and the disks have been replaced with coloured balls. Initially there are one or two empty tubes, and the coloured balls are all mixed up. The object is to sort the balls according to colour.

Example of start:

The app has 5 difficulty levels, from very easy to insane.
Well worth a look.

Write


Replace letters by digits to obtain a correct summation. The same letters always represents the same digit.

1) Pencil***/*****
WRITE
REPORT
——+
PENCIL

2) Pencil****/*****
NOTE
MEMO
PAPER
WRITE
—–+
REPORT

New puzzles are published at least once a month on Fridays. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars. You can check your solutions here and here.

Happy puzzling!

Eleusis


There are few good puzzle games. Puzzles rarely make good games, and good games rarely contain puzzles.

The first classical exception is mastermind. In recent years, Escape room shave become popular. A game which I learned as a student is Eleusis. This post concentrates on Eleusis. I wrote about Eleusis before in December 2013, you can find that post here.

The game of Eleusis was invented by Robert Abbott in 1956, and is totally different from such games as bridge or poker. Eleusis is played with a standard card deck of 52 cards. One player thinks of a secret rule and preferably writes this down. He plays two cards which obey the secret rule. All other players receive a number of cards, for example each player receives 5 cards.

The two cards are the beginning of a line of cards. The other players now take turns in playing a card to the end of the line. When a player plays a card, the Rule Inventor indicates whether the card obeys the rule. If it does, it is added to the end of the line. If it does not, the card is placed below the line and the player draws two extra cards from the deck. In both cases, the turn passes to the next player. The player who first gets rid of all his cards wins.

In the image above, the Rule Inventor started the row with 10 of clubs and jack of spades. The first player played 3 of spades, which was wrong. The next two cards, 3 of diamonds and 6 of spades, were also wrong. The fourth player tried 9 of hearts, which was correct.

The question is of course: With your hand depicted at the bottom, which of the 5 cards labeled A-E do you play?

You can check your solution here

The same coffee


The same coffee*/*****
My wife and I visited a restaurant. When my wife found a fly in the coffee, I called the waiter, who took the cup away and returned with a fresh cup.
As the waiter walked away, my wife angrily called him back and said: “You brought me the same coffee!”

How did she know?

You can check both your solutions here

New puzzles are published at least twice a month on Friday. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.

Cryptarithm – authors


Replace every letter by a digit to get a correct addition.

authors****/*****
cryptarithm-2016-12-01-authors-exercise

You can check your solution here

New puzzles are published at least twice a month on Friday. Solutions are published after one or more weeks. You are welcome to remark on the difficulty level of the puzzles, discuss alternate solutions, and so on. Puzzles are rated on a scale of 1 to 5 stars.

From 5 to 4


Consider the following figure:
matches 5 to 4 squares exercise

It is made of 12 matches, it is 1 figure, its circumference is 12 matches long and its surface is 5 squares. Can you reaarange them in such a way that it is still made of 12 matches, thats its circumference is 12 matches long, 1 figure but its surface is just 4 squares large?

You can check your solution here

Christmas puzzles


For Christians, Christmas means that God is not just a distant being who judges us miserable beings from far away up in heaven, but is someone who became like us: he was born as a baby in Bethlehem.

For most people in the western world, it means having one or more days off, meeting family, and having fun. Fur puzzlers, mean having time so solve a few brainteasers. For this occasion I dug up some classic christmas teasers.

In “The Canterbury puzzles” H.E. Dudeney tells of the squire’s Christmas puzzle party. One of them was:
1) Under the mistletoe bough
canterbutry puzzles 092
“At the party was a widower who has but lately come into these parts” says the record; and to be sure, he was an exceedingly melancholy man, for he did sit away from the company during the most part of the evening. We afterwards heard that he had been keeping a secret account of all the kisses that were given and received under the mistletoe bough. Truly, I would not have suffered anyone to kiss me in that manner had I known that so unfair a watch was being kept. Other girls were in a like way shocked, as Betty Marchant has since told me.” But it seems the melancholy widower was merely collecting material for the following little osculatory problem.

The company consisted of the squire and his wife and six other married couples, one widower and three widows, twelve bachelors and boys, and ten maidens and little girls. Now everybody was found to have kissed everybody else, with the following exceptions and additions:
No male, of course, kissed a male. No married man kissed a married woman, except his own wife. All the bachelors and boys kissed all the maidens and girls twice. The widower did not kiss anybody, and the widows did not kiss each other. The puzzle was to ascertain just how many kisses had been thus given under the misstletoe bough, assuming, as it is charitable to do, that every kiss was returned – the double act being counted as one kiss.

You can check your solution at here

2) The Christmas Geese
Squire Hembrow, from Weston Zoyland—wherever that may be—proposed the following little arithmetical puzzle, from which it is probable that several somewhat similar modern ones have been derived: Farmer Rouse sent his man to market with a flock of geese, telling him that he might sell all or any of them, as he considered best, for he was sure the man knew how to make a good bargain. This is the report that Jabez made, though I have taken it out of the old Somerset dialect, which might puzzle some readers in a way not desired.
“Well, first of all I sold Mr. Jasper Tyler half of the flock and half a goose over; then I sold Farmer Avent a third of what remained and a third of a goose over; then I sold Widow Foster a quarter of what remained and three-quarters of a goose over; and as I was coming home, whom should I meet but Ned Collier: so we had a mug of cider together at the Barley Mow, where I sold him exactly a fifth of what I had left, and gave him a fifth of a goose over for the missus. These nineteen that I have brought back I couldn’t get rid of at any price.”
Now, how many geese did Farmer Rouse send to market? My humane readers may be relieved to know that no goose was divided or put to any inconvenience whatever by the sales.

You can check your solution at here

Sam Loyd, of course, also had a nice christmas puzzle, though it disappoints me a bit that a quick scan revealed just one:
3) The Christmas Turkey
Loyd 136 the christmas turkey
Here is a pretty puzzle for the juveniles which affords considerable scope for ingenuity and cleverness. This Turkey Gobbler has led “Jolly old Santa Claus” a merry chase around the field, as shown by the tracks in the snow, before he was caught. You can see that they entered from the right side and did some lively circling before arriving at their present position, where the gobbler seems to be upon the point of surrendering. Our young folks are asked to study the situation carefully and to tell just how many times Santa Claus must have turned completely around during the chase, before pouncing upon the turkey?

You can check your solution at here

Please try to solve the puzzles on your own. You are welcome to remark on the puzzles, and I love it when you comment variations, state wether they are too easy or too difficult, or simply your solution times. Please do not state the soultions – it spoils the fun for others. I usually make the solution available after one or two weeks through a link, which allows readers to check the solution without the temptation to scroll down a few lines before having a go at it themselves.