解: (1)答案不唯一,如110,220
(2)当$a - b + c$是11的倍数或$a - b + c = 0$时,$\overline{abc}$能被11整除 理由:$\overline{abc}=100a + 10b + c = 99a + 11b + a - b + c = 11(9a + b)+(a - b + c),$$\because$ $99a + 11b$是11的倍数,$\therefore$ 当$a - b + c$是11的倍数或$a - b + c = 0$时,$\overline{abc}$能被11整除.