JMO STD V and STD VI

Answer:

If A and B are non zero digits, so

                                         A        B         0

                                         B        A         0

                                +       A        0         B

                                         B         0         A

2 x (A + B) x 100 + (A + B) x 10 + (A + B)

= (A + B) {200 + 10 + 1}

= ( A +B) x 211

So, divisible by 211.