Amount of Interest = $36 Rate of interest = 3% per annum Total time period for which the money was invested = 3 years Let us assume the Principal amount = x Then Interest = Principal * Rate of Interest * time 36 = x * 3% * 3 36 = 9x/100 36 * 100 = 9x 3600 = 9x x = 3600/9 = 400 So the initial sum of the money that was invested was $400.
