Best Answer Prime, 11 March 2013 - 12:24 AM

Going with the following assumptions as answers to my questions:

1. Leading zeros are allowed.

2. We work with the sum of numbers, not digits.

3. The school No. 7 is in Moscow in the vicinity of MSU (МГУ) and Vernadski Prospect.

I have a different proof of the same, which gives even more insight into divisibility rules, but it would take longer to explain.

We have another Divisibility puzzle going here: http://brainden.com/...re divisibility Go to the full post