A sum of Rs. 9800 amounts to Rs. 12600 at 9.33% p.a. simple interest in a certain time. What will be the simple interest (in Rs.) on a sum of Rs. 25200 at the same rate for the same time?

7200

Since rate and time are same for both conditions, simple interest  will be directly proportional to principal.

S.I. = 12600 - 9800 = 2800

P →      9800      :      25200

                7       :        18

  S.I. →     7                  ↓ x400

                ↓ x400        7200

              2800