Prove that 100 0's, 100 1's, 100 2's, 100 3's, 100 4's, 100 5's, 100 6's, 100 7's, 100 8's and 100 9's cannot be used in any form to make a perfect square.
I have no idea how to do this question. I was asked this question in a competition. A simple solution would be better.
1000 numbers (10 distinct digits * 100 each) can't be arranged in a square.