Simple Interest is money you can earn when you invest some money the principal for a period of time. It does not add any interest rate on the interest amount gathered on the principal amount. Mathematically:
Simple Interest : (Principal * Rate * Time)/100
Let us assume that you invest Rs100 for 2 year @ 5% interest. Then Simple Interest would be 100*2*5/100 = Rs10
Therefore Total amount after 2 years = 100+10 = Rs110
