Rs. 4800 becomes Rs. 7200 at a certain rate of interest compounded annually in 5 years. Find the amount at the end of 10 years.

10800

                Principal      :      Amount  

5yrs:           4800         :       7200

5yrs:               2          :           3

10yrs:            2²         :          3²

                      4          :         9

                      ⇓× 1200             ⇓

                   4800                   ⇓× 1200

                                           10800/-