Question

Alexandra invested $800 in an account paying an interest rate3.1% compounded continuously. Assuming no deposits or withdrawals are made, how much money , to the nearest hundred dollars, would be in the account after 20 years

Answer 1

$\bf ~~~~~~ \textit{Continuously Compounding Interest Earned Amount} \\\\ A=Pe^{rt}\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill & \ 800\\ r=rate\to 3.1\%\to \frac{3.1}{100}\dotfill &0.031\\ t=years\dotfill &20 \end{cases} \\\\\\ A=800e^{0.031\cdot 20}\implies A=800e^{0.62} \\\\\\ A\approx 1487.14\implies A=\stackrel{rounded~up}{1500}$