1. Let Principal $=P$, Rate $=R\%$ per annum, Time $=n$ years.
2. Rate compounded Annually :
Amount $=P\left(1+\frac{R}{100}\right)^{n}$
3. Rate compounded Half-yearly:
Amount $=P\left[1+\frac{R/2}{100}\right]^{2n}$
4. Rate compounded Quarterly:
Amount $=P\left[1+\frac{R/4}{100}\right]^{4n}$
5. Rate compounded Annually but time is in fraction, say $3\frac{2}{5}$ years.
Amount $=P\left(1+\frac{R}{100}\right)^{3}$ $\times\left(1+\frac{\frac{2}{5}R}{100}\right)$
6. When Rates are different for different years, say $R_{1}\%$, $R_{2}\%$, $R_{3}%$ for $1^{st}$, $2^{nd}$ and $3^{rd}$ year respectively.
Then, Amount $=P\left(1+\frac{R_{1}}{100}\right)$ $\left(1+\frac{R_{2}}{100}\right)$ $\left(1+\frac{R_{3}}{100}\right)$.
7. Present worth of Rs. $x$ due $n$ years hence is given by:
Present Worth $=\frac{x}{\left(1+\frac{R}{100}\right)}$