Monthly Archives: April 2014

Pattern codes – graphs


1) Graphs
What code goes to the question mark?
Pattern code graph exercise

You can check your solution here


A new puzzle is published every friday. The solution is generally published one week later. I welcome your reactions on these puzzles: are they too easy, too difficult, are there any multiple solutions? How long did you need to solve it?

Letter square


Conside the following square with letters.
Square alphabet

What number should go into the cell with the question mark?

Please try to solve the puzzles on your own. You are welcome to remark on the puzzles, and I love it when you comment variations, state wether they are too easy or too difficult, or simply your solution times. Please do not state the soultions – it spoils the fun for others. I usually make the solution available after one or two weeks through a link, which allows readers to check the solution without the temptation to scroll down a few lines before having a go at it themselves.

When you have solved this puzzle, you can check your solution here

You can find more puzzles like this one in our upcoming e-book on Logic Puzzles.

123 rectangles


Complete the diagram below according to the following rules:
* Every 3×1 rectangle has exactly one 1, one 2 and one 3.
* Identical numbers are never adjacent.
* Every row has three 1,’s three 2’s and three 3’s.
As for the second rule, identical numbers may not be adjacent horizontally or vertically, they may be adjacent diagonally.

Not adjacent abc exercise

I found this type of puzzle in the children section of “PUZZEL”, an extra end-of-year addendum to the Reformatorisch dagblad newspaper, and found it good enough for this blog.

You can check your solution at here

Please try to solve the puzzles on your own: your self confidence will grow. You are welcome to remark on the puzzles, and I love it when you comment variations, state wether they are too easy or too difficult, or simply your solution times. Please do not state the soultions – it spoils the fun for others. I usually make the solution available after one or two weeks through a link, which allows readers to check the solution without the temptation to scroll down a few lines before having a go at it themselves.