Category Archives: Inductive reasoning

Bongard problem (7)


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.

Bongard problem 7 rule 10 exercise

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.

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.

20160124_091224 20160124_091228

<pYou can check your solutions here

Coded germs


Pattern code germsOne 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.

The spy and the sentry


Castle DSC_0048A 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.

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.

Bongard problem 2015-11-20 exercise

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.

Bongard problem (5)


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.

Bongard problem rule 6 exercise 2015-12-02

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.

Bongard problem (3)


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.

Here is an example:
Bongard problem 2015-09-17 nr 4 exercise

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.

Bongard problems (2)


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.

Here is an example:
Bongard problem 2015-09-17 nr 3 exercise

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.

Bongard problems (1)


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.

Here is a trivial example:
Bongard problem 2015-09-15 nr 2 exercise

Here is something more resembling a puzzle:
Bongard problem 2015-09-15 nr 1 exercise

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.