Monthly Archives: January 2015

The house with eight kids

houseThere’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

2000px-Searchtool.svgInspector 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?
Incomplete multiplication exercise 1

2) The missing digits puzzle

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

Sam Loyd archeologist missing digits

3) Dudeney

In his “536 problems” British puzzle master Henry Dudeney presents the following problem:
incomplete division dudeney 144

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.


A Sojuko can be considered as part of the Sudoku family in the sense that the 3×3 square contains each of the digits 1 to 9 exactly once. Some of the digits have been omitted, and the puzzle is to restore the missing digits. As clues four circles are given, holding the sum of the numbers in the squares around them. The solutipon techniques however are reminiscent of Kakuro.

Sojuko number 1
Sojuko 20141214 nr 1 exercise

Sojuko number 2
sojuko 20141215 nr 1 exercise

I found them in “Terdege”, a puzzle add-on of the newspaper “Reformatorisch dagblad”.

You can check your solution here and here

Old year – New Year

It is always hard to come up with original puzzles, let alone with a puzzle that has to do with Christmas or new year. Any way: best wishes for 2015 to all of you!

Let’s have a simple problem from the orient. Did you notice that medieval sultans always seem to have an ample supply of beautiful daughters? And that they invariably have strange ways to choose their son-in-law?

This one is no exception. His kingdom had an extensive seashore, and he said to four young men interested in the hand of his daughter: Along the coastline I own many fishing boats. But there is something very peculiar with the number of fishing boats:
when the number is divided by 2, the remainder is 1,
when the number is divided by 3, the remainder is 2,
when the number is divided by 4, the remainder is 3,
when the number is divided by 6, the remainder is 5,
when the number is divided by 7, the remainder is 6
when the number is divided by 8, the remainder is 7
when the number is divided by 12, the remainder is 11
when the number is divided by 14, the remainder is 13
when the number is divided by 18, the remainder is 17
when the number is divided by 21, the remainder is 20
when the number is divided by 24, the remainder is 23
when the number is divided by 28, the remainder is 27
when the number is divided by 32, the remainder is 31
How many fishing boats are there in my kingdom?

You can check your solution here