- Let Principal = P, Rate = R% per annum, Time =
*n*years. *When interest is compound Annually:*Amount = P 1 + R *n*100 *When interest is compounded Half-yearly:*Amount = P 1 + (R/2) *2n*100 *When interest is compounded Quarterly:*Amount = P 1 + (R/4) *4n*100 *When interest is compounded Annually but time is in fraction, say 3 years.*Amount = P 1 + R 3 x 1 + R 100 100 *When Rates are different for different years*, say R_{1}%, R_{2}%, R_{3}% for 1^{st}, 2^{nd}and 3^{rd}year respectively.Then, Amount = P 1 + R _{1}1 + R _{2}1 + R _{3}. 100 100 100 *Present worth of Rs.**x*due*n*years hence is given by:Present Worth = *x*. 1 + R 100