**1 to 9**^{**/*****}

Fill the grid with each of the numbers 1 to 9 exactly once :

New puzzles are published twice a month on Fridays.

You can check your solution here

**1 to 9**^{**/*****}

Fill the grid with each of the numbers 1 to 9 exactly once :

New puzzles are published twice a month on Fridays.

You can check your solution here

Which rule satisfies the 6 figures on the left but is obeyed by none of the 6 figures on the right?

*1)Bongard problem 10*^{***/*****}

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 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 solution here

You can find more Bongard problems here on this site and at Harry Foundalis’ site.

New puzzles are published at least twice 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.

**1) Make 2019 (1)**^{**/*****}

Take the series 1,2,3,4,5, etc. Insert + and – signs in between the numbers to make 2019. Do not use brackets. What is the shortest series?

**2) Make 2019 (2)**^{***/*****}

Take the digits, 0-9. Keep them in *exactly this ascending sequence* and combine them wit +, -, *, /, ^, brackets and/or ! to make 2019.

**3) Make 2019 (3)**^{***/*****}

Take the digits, 0-9. Order them in *descending sequence* (9, 8, 7, down till 0) and combine them with +, -, *, /, ^, brackets and/or ! to make 2019.

**4) The digits 2, 0, 1, and 9**^{***/*****}

The year 2019 is made up of the digits 2,0,1 and 9. Combine them with all mathematical and arithmetic operators to make every number 0-20. For example: 0*1*2*9=0.

**5) The digits 2, 0, 1, and 9**^{***/*****}

The 9 is the largest digit in “2019”. It is the square of the sum of the three other digits (9 = (2+0+1)^2). What is the next year when the largeest digit is euqal to the square of the other three digits?

You can check your solutions here

New puzzles are published at least twice 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.