It has come to my attention that some unfortunate Americans hadn't grasped
Compound interest by the age of 22, so in the interest of public welfare I am
posting the following:

Interest and Exponential Growth

The Compound Interest Equation

   P = C (1 + r/n) nt

where
   P = future value
   C = initial deposit
   r = interest rate (expressed as a fraction: eg. 0.06)
   n = # of times per year interest in compounded
   t = number of years invested

Simplified Compound Interest Equation
When interest is only compounded once per yer (n=1), the equation simplifies to:

   P = C (1 + r) t

Continuous Compound Interest
When interest is compounded continually (i.e. n --> ), the compound interest
equation takes the form:

   P = C e rt

Demonstration of Various Compounding
The following table shows the final principal (P), after t = 1 year, of an
account initally with C = $10000, at 6% interest rate, with the given
compounding (n). As is shown, the method of compounding has little effect.
n    P
1 (yearly)    $ 10600.00
2 (semi-anually)    $ 10609.00
4 (quarterly)    $ 10613.64
12 (monthly)    $ 10616.78
52 (weekly)    $ 10618.00
365 (daily)    $ 10618.31
continuous    $ 10618.37
Loan Balance
Situation: A person initially borrows an amount A and in return agrees to make n
repayments per year, each of an amount P. While the person is repaying the loan,
interest is accumulating at an annual percentage rate of r, and this interest is
compounded n times a year (along with each payment). Therefore, the person must
continue paying these installments of amount P until the original amount and any
accumulated interest is repayed. This equation gives the amount B that the
person still needs to repay after t years.

   B = A (1 + r/n)nt - P     (1 + r/n)nt - 1 (1 + r/n) - 1

where

   B = balance after t years
   A = amount borrowed
   n = number of payments per year
   P = amount paid per payment
   r = annual percentage rate (APR)
   
Do you *get* *it* now *Stoopid* ?????

Jeez, and there you was promising to take care of people's money. I can
seriously see why the Chinese are getting rid of their dollars.    

Firebird

Never trust anybody who is too sophisticated to own a rubber chicken.

http://www.veloceraptor.free-online.co.uk/masters.html