formular for compound and simple intrest
Since this is not my area of expertise, I searched Google under the key words "compound simple interest formula" to get these possible sources:
http://en.wikipedia.org/wiki/Compound_interest#Mathematics_of_interest_rates
http://math.about.com/od/businessmath/ss/Interest.htm
http://www.moneychimp.com/articles/finworks/fmfutval.htm
http://www.compound-interest-formula.com/compound-simple/compound-simple-comparison
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps. Thanks for asking.
The formulas for calculating compound interest and simple interest are as follows:
Simple Interest:
Simple Interest = Principal × Interest Rate × Time
Compound Interest:
Compound Interest = Principal × (1 + Interest Rate)^Time - Principal
To calculate simple interest, you need to know three variables: the principal amount (the initial amount of money), the interest rate (expressed as a decimal or percentage), and the time period (in years or any other unit of time). Multiply the principal by the interest rate and then multiply the result by the time to find the simple interest.
For compound interest, you also need the same three variables: principal, interest rate, and time. To calculate compound interest, add 1 to the interest rate and raise the result to the power of the time period. Then, multiply this by the principal and subtract the principal amount. This will give you the compound interest.
Note: The interest rate should be expressed in decimal form, so if given in percentage, divide it by 100 before using it in the formula.