Find all possible two digit positive integers N for which the sum of digits of 10^{N}  N is divisible by 170.
(In reply to
Solution by Dej Mar)
Hi,
I am unsure about the solutions here...20,39,58,77,96. Not have a calculator so I can't give the full numbers but my thinking goes like this:
1) To be divisible by 170, the last digit of this number has to be zero. It needs to be a multiple of ten.
2) 10 to any power (X) will be a multiple of ten. If you then subtract that number, you will then only have a result multiple of ten if X is a multiple of ten.
Therefor: 20 could be a posible solution, but 39,58,77,96.
This disagrees with multiple comments. What am I missing?
Patrick

Posted by Patrick
on 20060718 13:39:29 