Hi, I have recently encountered a problem I was unable to solve. I have tried everything and none of it worked.

Please help. The problem goes like this:

Prove that every natural odd number 'n' undividable by number 5, divides at least one of the numbers

1, 11, 111, 1111, 11111, 111111, 1111111, 11111111, 111111111, 1111111111, ....... etc.