Move 1 matchstick to get 6 squares.
That’s right, your are not allowed to add a matchstick, to break or bend one.
You can check your solution here
Bongard problem (6)
The Russian scientist M.M. Bongard published a book in 1967 that contains 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 conform to a certain rule. Each and every box on the right contradicts this rule. Your task, of course, is to figure out the rule.
This weeks problem is from the hand of our daughter Margreet.
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<pYou can check your solutions here
1-8
The Dutch reformed-christian ‘Reformatorisch Dagblad’ twice a year publishes an extra puzzle issue for its subscribers. This weeks puzzle type is 1-8, invented by Marijke Balmaekers, and published in the childrens section of the ‘Vakantie Doe Boek’ of the reformatorisch Dagblad.
The numbers one to eight have been arranged in a 5×5 grid in such a way that:
- Each of the numbers one to eight is used exactly once
- There are always one or two numbers in every row, column or diagonal
- the sum of the numbers is listed as a clue at the end of the row/column/diagonal
Example:
number 1
number 2
number 3
Alphametic – Untrue (3)
In the following addition, replace every letter with a number. The same letter always represents the same digit, and no digit is represented by more than one letter.
You can check your solutions here
Matchsticks – 4 equal areas
Matchsticks problems usually fall into one of 2 categories: roman or digital numbers, or geometrical problems. This weeks puzzle is one which belongs to the geometrical group.
Add 8 matches to divide this square into 4 areas of equal size and shape. No matches may be broken or cross each other.
This problem is not my own, but i was recently reminded by it by a puzzle on dawies blog.
A new puzzle is posted every friday. You are welcome to comment on the puzzles. Solutions are added at the bottom of a puzzle after one or more weeks.
You can check your solutions here
Coded germs
One of the type of puzzles taht has become a trademark of this blog are ‘coded patterns’
Which code goes to the question marks?
You can check your solution here
You are welcome to remark on the puzzle: its wording, style, level of difficulty. I love to read your solution times. Please do not spoil the fun for others by listing the solution. Solutions will be posted after one or more weeks.
Letterboggle (2)
In January 2014, I published a one puzzle blogpost on Letterboggle. Going through old notebooks, I discovered some more of these puzzles.
Let me restate the rules:
* All 26 letters of the alphabet have been used exactly once;
* two letters which are consecutive in the alphabet are always adjacent either horizontally, vertically or diagonally. Hence the alphabet forms a kind of snake throughout the firgure;
* The letter A does not need to be adjacent to the letter Z;
* A letter in the margin is present in the same row (if margin letter is adjacent to a row), in the same column (if the margin letter is on top or bottom of a column) or in the same diagonal (if the mnargin letter is in one of the corners);
Letterboggle (1)*
Letterboggle (2)*
Letterboggle (3)**
Note that not all border fields contain a clue. This is on purpose.
Personally I would find alphabet snake a better name, but
The spy and the sentry
A spy wanted to enter a castle, but this castle was guarded by a sentry. Only those who knew the password, were allowed to enter. The spy hid himself in the bushes near the guardhouse of the sentry, so that he could overhear the password.
The baker approached, and the sentry called:
‘If I say 12, what do you reply?’
‘6’
‘You may pass.’
The smith approached, and the sentry called:
‘If I say 6, what do you reply?’
‘3’
‘You may pass.’
The spy concluded: ‘I know enough’
With a long detour he went back, disguised himself as a grocer and approached the sentry. The sentry called:
‘If I say 4, what do you reply?’
‘2’
The spy was taken prisoner.
What should he have replied?
I would like to thank our daughter Margreet for passing on this nice problem, which she heard from Professor Jochem Thijs. Alas he did not reply to my question if he invented this puzzle or not. If he is not the inventor, and someone knows the original source, I would be grateful.
You can check your solution here
You are welcome to remark on the puzzle: its wording, style, level of difficulty. I love to read your solution times. Please do not spoil the fun for others by listing the solution.
Problems = Puzzles?
Bongard problem (4)
The Russian scientist M.M. Bongard published a book in 1967 that contains 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 conform to a certain rule. Each and every box on the right contradicts this rule. Your task, of course, is to figure out the rule.
You can check your solutions here
You can find more Bongard problems at Harry Foundalis site, and I intend to publish more problems in the future.
A new puzzle is posted every friday. You are welcome to comment on the puzzles. Solutions are added at the bottom of a puzzle after one or more weeks.
justpuzzles 