At a certain simple rate of interest, a given sum amounts to Rs 13920 in 3 years, and to Rs 18960 in 6 years and 6 months. If the same given sum had been invested for 2 years at the same rate as before but with interest compounded every 6 months, then the total interest earned, in rupees, would have been nearest to
Solution
SI for the extra years , so SI per year .
Principal . Rate .
Half-yearly compounding for 2 years: 4 periods at .
.
Interest .