Interests

Denote $P$ the principal, $r\%$ the interest rate per annum, $t$ the number of years, $I$ the interest and $A$ the amount.

1. $I=P\times r\%\times t$
2. $A=I+P$
3. $A=P(1+r\%\times t)$

Denote $P$ the principal, $r\%$ the interest rate per period, $n$ the number of periods, $I$ the interest and $A$ the amount.

1. $A=P(1+r\%)^n$
2. $I=A-P$

Same Topic:

Growth and Decay Identities of Squares Percentage Changed Profit and Loss