Cryptarithms

Cryptarithms, alphametics, verbalarithmetic are some of the names of a type of puzzle, where two, three or more words are given, and each letter must be replaced by a single digit. The most well known of this is:
1) Dudeneys classic^**

 SEND
 MORE
-----+
MONEY

Replace each letter with exactly 1 digit and make it a correct addition. The example above is from Henry Dudeney.

(Solution: 10)

Verbal arithmetic puzzles are quite old and their inventor is not known. An example in The American Agriculturist[2] of 1864 makes the popular notion that it was invented by Sam Loyd unlikely. The name crypt-arithmetic was coined by puzzlist Minos (pseudonym of Simon Vatriquant) in the May 1931 issue of Sphinx, a Belgian magazine of recreational mathematics. In the 1955, J. A. H. Hunter introduced the word “alphametic” to designate cryptarithms, such as Dudeney’s, whose letters form meaningful words or phrases.

There are several types of cryptarithms. One of them is them is the double true. This type of cryptarithm shows an addition that is true in words, but can also be deciphered as a cryparithm. This puzzle comes from N. Tamura, who wrote a program to search for puzzles with a unique solution.
2) DOUBLE TRUE:^**

 THREE
  FIVE
  FIVE
 SEVEN
   TEN
------+
THIRTY

(Solution: 30)

3) Math formulas^* are another subcategory.
This one was first published in Sphinx magazine, and republished by Jorge A C B Soares. He mentions M. Van Esbroeck as the author, and january 1933 as the date of first publication.

 A B C = C4
 B C A = D4

(Solution: 40)

Cryptarithms are of course language dependent. However, they are not limited to the English language. The booklet CIJFERWERK (digit work), written by J. van der Horst, published by Born periodieken, date unknown, isbn 8 710838 100910, has some 200 dutch cryptarithms. In Germany they are called “Kryptogramm”, in French “Cryptarithme”, or d’alphamétique. I see articles on them in the Japanese wikipedia, where they give the following example:
4) Japanese^*

　大宮
×大宮
大井町
横浜　
-----+
浜松町

Please forgive me that my Japanese is insufficient to discover the author.

(Solution: 70)

5) List^**
Lists are another subcategory of this puzzle type. Lists are composed of a number of items in category, followed by the name of the category, which equals to the sum of the items. In a good list items are unique, taht is, they appear only once.

Here is a non unique list, that is a list with items that appear more than once:

APPLE
 PEAR
 DATE
APPLE
 PEAR
 DATE
APPLE
 PEAR
 DATE
APPLE
 PEAR
 DATE
-----+
FRUIT

(Solution: 50)

Links

1. online puzzle solver
2. Mike Keiths site
3. Sphinx collection
4. http://bach.istc.kobe-u.ac.jp/puzzle/crypt/out/eg-num.out

Pattern codes – Diagonals

What is the code for the fifth figure?

This weeks puzzle is pretty easy, I admit. I hope next weeks puzzle will be more of a poser.

You can check your solution.

Shikaku

Shikaku puzzles are puzzles which can be found in some magazines. They were invented by Nikoli, a Japanese puzzle firm. Allthough they can be drawn in black and white, the colored versions seem to be more popular. There are several websites offering them – see below They are also known as Shikaku ni Kire, rectangles, Divide by Squares and Divide by Box.

The basic is a square or rectangle which has been subdivided into rectangles. The border lines are not shown in the exercise – this is what the solver has to find out. The sizes of the rectangles are given as clues.

Example:

The solution:

As you can see in the examples above:
(1) Only rectangles are used;
(2) Every rectangle has exactly 1 square indicating its size;

Here are some puzzles with them:
1) Problem 6×6

2) problem 7×7

3) problem 12×12

There are several apps for your android smartphone or ipad around. Sites which offer shikaku puzzles are:

1. http://www.nikoli.com/en/puzzles/shikaku/
2. http://www.mathinenglish.com/Shikaku.php

You can check your solutions here, here and here

Number squares

1) Number square^*
Find the missing number:

solution: Here)

Inspector Simon Mart and the stolen matchstick

‘I was on the island of Lotl Ire Esain in the Archipellago,’ Inspector Simon Mart wrote in his text editor, ‘where I encountered a strange case. The island is remarkable ny its population, which consists of two distinct groups: Liars, who will always Lie but are honest in the sense that they will never steal, and Thieves, who will often steal but who are absolutely honest in that they will always tell you the truth.’

He continued to write:
In one case brought to my attention, a person had been robbed of a box of burnt matchsticks. Now that may sound ridiculous, but the island is devoid of trees and all wood must be imported so it is considered a criminal offense.

Two suspects were brought in, and it had already been established that one of them had to be the criminal. The policeofficer who brought them in introduced them as Peter and Paul.
‘What the hack,’ I thought. ‘Would it have been the same two persons or is every Jack and Joe called Peter and Paul here?’ Anyway, hoping that the thief would simply asnwer truthfully, I asked Peter: ‘Dit you steal the matchstick?’
But Peter simply answered: Paul is a Liar.
Asking Paul the same question to Paul, Paul replied: ‘Peter is a thief’.

Who stole the matchstick?

If you wish you can check your solution.

What comes next?

What number comes next in the following sequence?

56789
51317
548
…

You can check your solution here

Inspector Smart on the Isle of Thieves and Liars

After his adventure on the island of Koaloao, Inspector Simon Mart traveled on to the second island in the Logico archipelago, Lotl Ire Esa.

The population of this island, he knew, was very peculiar; it consisted of two distinct groups, each with his own rigid disposition, and the inspector suspected it was a genetic mutation.
One group on this island was called Thieves: they had an uncontrollable tendency to steal, but they would always tell the truth. The other group was called Liars, they never stole anything but would always lie.

1) The scepter of dignity
After checking into his hotel, he had gone straight to the police headquarters in the capital. In the case before him, there were two suspects, Peter and Paul. The crime under investigation was the theft of the Scepter of Dignity, a rod made of used matchsticks, and dating back to 1997.

Peter: Paul is a Thief. But he did not steal the scepter.
Paul: Peter is a Thief. And Peter stole the scepter.
It was already certain that one of the two had stolen the scepter. Who is guilty?

If you wish you can check your solution.

The house with eight kids

There’s a house with 8 kids, who are all at home.

Amber is annotating a paper;
Betty is bathing;
Charles is cooking;
Dorothy is playing draughts;
Elly is eating;
Ferdinand is training his fish;
Gina is watching a fashion show on television;

What is Henry doing?

This puzzle is based on this one, but with a subtle twist.

You can check your solution here

Inspector Simon Mart and the camper at Trafalgar square

Inspector Simon Mart looked at the blank screen of the word processor in front of him. He really wanted to write down something about the interesting cases he had explored at the isle of KoaLoao. He was glad, of course, to be back in London, back in the familiar office, back between the familiar colleagues at Wales Yard, back in his own familiar office room with the familiar mug of the familiar undrinkable drab of coffee.
Just as a blink of inspiration on how to start popped up, a superintendant dropped in, wiping out any trace of inspiration about how to start.
‘Three suspects of the theft of the copper kettle of a camper on Trafalgar Square, Simon. Can you question them? Boring cases, of course, for you, after your holiday in Archipelagio.’
‘The only one who needs to be questioned is the camper,’ Simon replied dryly. ‘Why would any one in his right mind want to put up his tent there? Did he obstruct the traffic? And why would he have a copper kettle where every camper uses plastic stuff?’
‘I admit we made a Strategic Mistake in letting that guy go,’ the superintendant replied with a devilish smile, ‘He didnt seem to have obstructed the traffic – he put up his tent in the fountain. But the three suspects we rounded up are all we have. Oh, and we are sure one of them did it.’ Having said that, he showed in Mighty Mike, Ron Rubbish and Sluggy Sarah.
Inspector Simon asked them one simple question: ‘Who did it?’
Mighty Mike replied: Ron Rubbish did it.
Ron Rubbish answered: Sluggy Sarah took it.
Sluggy Sarah said: I’m innocent.
Now, assuming only the thief lied, who should the inspector keep in custody for further interrogation?

You can check your solution here

The coffee stain, the archeologist and the reverend

1) The coffee stain

^**
When I visited an old friend of mine, with his laptop out of order, he had just completed a simple multiplication with pencil and paper. Unfortunately, I spilled some coffee over it. Can you pelase help him to complete the multiplication again?

2) The missing digits puzzle

^**
In his “Cyclopedia of 5000 Puzzles, tricks and conumdrums” American puzzle master Sam Loyd presented the following puzzle:

Sam Loyd tells a long story about Mormon rock, and in his reprint Martin Gardner skipps this part. I will not follow his example in order to preserve the history, but I do not want to offend anyone, and one should take notice that Sam Loyd was also a master in inventing stories, as can be illustrated with the example on the Swiss flag. Don’t take anything he tells seriously.

Once again discussion has been revived concerning the meaning of the hieroglyphic numbers engraved on Mormon Rock. Mormonism originated only so far back as 1830, so if these weather beaten figures have anything to do with the Latter Day Saints there should be thousands of persons qualified to tell all about them, unless, as some claim, they pertain to the hidden mysteries.
The Mormons migrated in 1838 From Kirtland, O., to Nauvoo, the “City of Beauty” in Illinois and to Salt Lake in 1848. When they left Nauvoo they boasted that their line of march would be twenty four miles long, and was te be headed by a printing press to issue the daily orders of the prophet. It was stated that they were divided up into numerous companies, each one headed by one of the prophet’s wives, and the mysterious fiugures on the Mormon Rock were supposed to give the number of pilgrims in each division.

The figures look like a sum in division engraved upon a sandstone rock. Most of the numbers are illegible, but as some are sharp and clear it is to be assumed that the others were erased maliciously or for a purpose. It is now claimed that either through accident or design the eight legible numbers furnish a key to the mystery, and that the whole is a sum in long division which tells just how many pilgrims marched with each division, and incidentally gave a clue to the number of the prophet’s patrimonial ventures.

It is a remarkable coincidence that the remaining numbers furnish a cluse which easily solves a most interesting historical puzzle, for if you write down the sum in long division, mixing stars with the legible figures as shown, you should speedily be able to guess the numbers which have been erased so that the sum will prove. It reaaly looks as if there should be scores of correct answers, and yet so far as I am aware, but one satisfactory restoration of the missing numbers has been suggested.

Just in case the illustration is not clear, here is a more abstract image of the problem:

3) Dudeney

^**
In his “536 problems” British puzzle master Henry Dudeney presents the following problem:

He tells it was send to him by the reverend E.F.O. It is, he tells, the first example he has seen of one of those missing-figures puzzles.

You can find these and other puzzles like these in the second edition of my e-book with numbers puzzles.