Question

what is the balance of $100 with an annual compound interest of 8% for 40 years?

Answer 1

$\begin{gathered} A=\lbrack p(1+\frac{r}{100})^{n\rbrack} \\ =\lbrack100(1+\frac{8}{100})^{40\rbrack} \\ =100(1.08)^{40} \\ =100\times21.72 \\ =2172 \end{gathered}$