Exercise :: Compound Interest - Important Formulas
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 R1%, R2%, R3% for 1st, 2nd and 3rd year respectively.
Then, Amount = P 1 + R1 1 + R2 1 + R3 . 100 100 100
Present worth of Rs. x due n years hence is given by:
Present Worth = x . 1 + R 100