Aptitude :: Compound Interest

  1. Let Principal = P, Rate = R% per annum, Time = n years.

  2. When interest is compound Annually:

       Amount = P 1 + R n
    100

  3. When interest is compounded Half-yearly:

        Amount = P 1 + (R/2) 2n
    100

  4. When interest is compounded Quarterly:

        Amount = P 1 + (R/4) 4n
    100

  5. When interest is compounded Annually but time is in fraction, say 3 years.

        Amount = P 1 + R 3 x 1 + R
    100 100

  6. 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

  7. Present worth of Rs. x due n years hence is given by:

        Present Worth = x
    1 + R n
    100