You can put this solution on YOUR website! There aren't any. This is because:
a + b + c = (1/2)(100a + 10b + c)
2a + 2b + 2c = 100a + 10b + c
98a + 8b - c = 0.
98a + 8b = c
Since a must be at least 1 (since it's a three-digit number) then c is at least 98, which wouldn't work.