The simple interset on a sum for 5 years is `3/5` of the sum. The rate per cent per annum is

The simple interest on a sum for 5 years is 2/5 of the sum. The rate per cent per annum is

The simple interest on a sum of money for 5 years is 3/5 of the sum. Find the rate per cent per annum.

The simple interest on a sum for 5 years is one fourth of the sum. The rate of interest per annum is

The comound interest on a certain sum for 2 years at 10% per annum is 1260. The simple interest on the same sum for double the time at half the rate per cent per annum is