This is another 2-minute problem that kids will enjoy. Found this one again in Martin Gardner’s The Colossal Book of Short Puzzles and Problems.
Look at the figure below, which has 8 empty circles.
You need to place digits 1 through 8 into these circles with no repetition. No two adjacent numbers (e.g. 3 and 4) can be in circles that are connected by a line.
There is only one solution (without mirror images) and there is a method to the madness here.
As always, please send your answers as comments within the blog (preferred), or send an e-mail to firstname.lastname@example.org. Please do share the puzzle with others if you like, and please also send puzzles that you have come across that you think I can share in this blog.
Happy digital scramble for brunch today!
C and F independently are connected to all except one circle. So, C and F cannot have two adjacent numbers. So C is 1 and F is 8. So A is 7 and H is 2.
3,4,5,6 needs to be placed in B,D,E,G
B and D cannot be 6
E and G cannot be 3
Since the image is symmetric across vertical line, lets say B is 3. If E is 6, and D and G become 4 and 5 which is not possible. So G is 6. So D is 4 and E is 5.
So, A is 7, B is 3, C is 1, D is 4, E is 5, F is 8 and G is 6.