I am thinking of a fifty-digit number divisible by 239, of which, each digit is the same, except the ones digit. What is the ones digit?
I thought: "hmm, I need to know about the first 49 digits, what if I break it into 7-digit chunks. What's 1111111/239?"
Turns out it divides evenly.
So it will divide the first 49 digits evenly no matter what digit they are. The last digit must be a 0.
Posted by Jer
on 2005-05-13 16:55:53