The simple interest on a sum of money is 2/5 of the sum. If the number of years is numerically half the rate per annum, then find the rate percent per annum.
Let P = 5 units and Simple Interest = 2 units T = R/2 SI = (P × R × T)/100 => 2 = (5 × R × R)/(100 × 2) => R = 8.9%