Sunday, April 24, 2011

Lucky numbers

A bus ticket is considered to be lucky if the sum of the first three digits equals to the sum of the last three (6 digits in Russian buses).

Prove that the sum of all the lucky numbers is divisible by 13.

***** UPDATE! *****

1 comment:

  1. did some work on this but nothing substantive so far

    e.g. aa (2-digit numbers = 9); aaaa = 615; aaaaaa = 50,412;