Bongard Christmas

December 18, 2020Bongard problemsTeun Spaans

Bongard problems were first devised by the Russian computer scientist Mikhail Moiseevich Bongard 1924–1971. The first publication I know was in a 1967 book. They were intended to be a test for artificial intelligence. In order to keep things controallable, he based them on geometry, which he supposed was culture free.

This months puzzle is absolutely not culture free. Personally, I suppose real artificial intelligence should also be able to deal with cultural aspects.
I wish you all a Merry Christmas!

Bongard problem Christmas^**/*****

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.

Rule finding game

December 4, 2020Inductive reasoningTeun Spaans

Today, have a look at these 6 numbers. Not difficult, huh?

1) devise five different rules^**/*****
Now devise five different rules to divide these 6 numbers into two groups of three numbers.
Spoiler: one rule might be: even numbers go left, odd numbers go right. Or : both groups add up to 15.

2) devise eight different rules^**/*****
Devise as many dufferent rules to divide these 8 numbers into 2 groups of 4 numbers.

This game was described by “The Barrcast” in a youtube film titled “Rule finding games”.

Bongard problem 63

November 20, 2020Bongard problems, Inductive reasoningTeun Spaans

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.

1)Bongard problem geometry 63^**/*****

Matchstick puzzles

November 6, 2020MatchsticksTeun Spaans

It’s a while ago since we had matchstick puzzles. And the last series we had, were with numbers 0-9 as found on digital watches.

This puzzle is a bit different. You see
4 (or 6) parallelograms^*/*****
Move to matches to make 3 squares

What’s next?

October 30, 2020Inductive reasoningTeun Spaans

Here’s a quicky, with thanks to my son in law Kevin:

No, the answer is not 6!

What’s next

October 16, 2020Arithmetic, Inductive reasoning, NumbersTeun Spaans

This weeks quickie is inspired by a tweet by Laurie Rubel.
What’s next^**/*****
14, 17, 23, 24, 26, 30, 33, …

A new puzzle is published at least twice a month on Friday. You can check your solution here.

Bongard problem 61

October 16, 2020Bongard problemsTeun Spaans

1)Bongard problem geometry 61^****/*****

Quento

October 2, 2020ArithmeticTeun Spaans

While cleaning up old newspapers in someone’s house I came across a puzzle called “Quento” in the Dutch newspaper “Algemeen dagblad”.

The basics of this puzzle are simple calculations. What sets it a bit apart from other puzzles is that the answers are given, and that you have to find the exercise.

Example:

You have to find a calculation for each of the numbers on the right by going from a number to a + or – sign and on to another number. If necessary, you may add additional +/- signs and numbers, as long as you don’t use the same number or sign twice.

What you may do:

Not allowed is:

Of course there is a website, and an app for both Android and Ipad. Personally I think the exercises are too easy, though no doubt they can be increased by adding size and moving to higher numbers, as shown in our 4th problem. In the app I did see higher numbers, in the sense of multiples of 3, 4, 5 , and so on, but I didn’t see larger sizes, as in our fourth problem. That may be because I didn’t purchase the app and just used the free version.

Quento 2^*/*****

Quento 3*/*****

Quento 4**/*****

You can check your solutions at href=”https://justpuzzles.wordpress.com/Solutions to puzzles 501-750/#516″>here.

Dutch double true alphametics

September 18, 2020alphameticTeun Spaans

An alphametic is an addition in words, verbal arithmetic. It is a puzzle in which you have to replace the letters by digits, and get a correct calculation.
This Friday I bring you a number “double true” alphametics from the dutch language.

1) Three^**/*****
EEN + EEN + EEN = DRIE

2) Six^*/*****
EEN + EEN + EEN + EEN + EEN + EEN = ZES

3) Seven^**/*****
TWEE + TWEE + EEN + EEN + EEN = ZEVEN

4) Nine^***/*****
DRIE + DRIE + DRIE = NEGEN

5) Thirty (1)^**/*****
TWAALF + ELF + DRIE + TWEE + TWEE = DERTIG

6) Thirty (2)^***/*****
ELF + NEGEN + TWEE + TWEE + TWEE + TWEE + TWEE = DERTIG

Though you don’t need them, here is the list of Dutch counting words:
1 Een
2 Twee
3 Drie
4 Vier
5 Vijf
6 Zes
7 Zeven
8 Acht
9 Negen
10 Tien
11 Elf
12 Twaalf
13 Dertien
20 Twintig
30 Dertig

Lyfoes

September 4, 2020UncategorizedTeun Spaans

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: