Question

​$10000 is compounded semiannually at a rate of 10​% for 20 years.

Answer 1

`\bf ~~~~~~ \textit{Compound Interest Earned Amount} \\\\ A=P\left(1+(r)/(n)\right)^(nt) \quad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill &\$10000\\ r=rate\to 10\%\to (10)/(100)\dotfill &0.10\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{semiannually, thus twice} \end{array}\dotfill &2\\ t=years\dotfill &20 \end{cases}`

`\bf A=10000\left(1+(0.10)/(2)\right)^(2\cdot 20)\implies A=10000(1.05)^(40)\implies A\approx 70399.88712125`