Is it possible to write the numbers 1,2...,9 on the perimeter of a circle so that sum of any 2 consecutive numbers is NOT a multiple of 3,5 and 7?

Question

phi · Answer

are they asking to permute the numbers 1...9  on a circle, so that no consecutive sum is a multiple of 3,5 or 7 ?

anonymous · Answer

Yes
lets say this is your order 123456789 than 1-2, 2-3, ...., 8-9 and 9-1 are consecutive numbers

anonymous · Answer

Phi I know the solution, it was a good challenge for me to solve. That is why I posted :)

phi · Answer

If I *really* had to solve it, I would write a program and do a tree search.

anonymous · Answer

Well there are finite many solutions so a computer can check them easily. However you do not need a PC to solve it. Your brain is the ultimate tool

phi · Answer

1     3     8     5     6     2     9     4     7