Hello dijinj

I'm sorry, I just don't understand what the question means?So a 'sign' contains digits 1 to 5. How many digits make up a sign? All of them? Just one? What?What is meant by a 'number'? A set of digits? A single digit? What?...numbers can be repeated but signs cannot be repeated...

Unless you can define much more accurately what you mean, it's not going to be possible to give you any help.

Do you have a statement of the original question? If so, let's see it in full, and we'll take it from there.

Grandad