Repeaters

Choose any 3 digits and make a 6 digit number by repeating the 3 digits in the same order (e.g. 594594). Explain why whatever digits you choose the number will always be divisible by 7, 11 and 13.

Problem



Choose any 3 digits and make a 6 digit number by repeating the 3 digits in the same order (e.g. 594594).

Whatever digits you choose the number will always be divisible by 7 and by 11 and by 13, in each case without a remainder.

Can you explain why?