Take the first nine natural numbers (is sunt, 1 up to and including 9). Now try to find a way to place these nine numbers in the squares in the figure below, such that for each circle the sum of the numbers in it equals 11. You have to use each of these ten numbers exactly once.
If you figured out how to do this, now try it for a circle sum of 13, and once again for a circle sum of 14.
This edition’s puzzle seems easy, but actually turns out to be harder than expected. Namely, if you would have to verify each possible arrangement, you would have to check 24,192 candidate solutions! Hence you better find a way to reduce this amount drastically…
Can you figure out the puzzle?
Please enter your solutions at www.Nekst-Online.nl/Puzzle. A crate of beer or a delicious pie, whichever the winner prefers, will be waiting for whoever has sent the best (partial) solutions. Please note that, as before, every recipient of this magazine is eligible to send in their solutions, so members of the department are invited to participate as well. Good luck!