Question

What is interest earned on 3500 invested at 6% compounded quarterly or 12 years

Answer 1

`\bf \qquad \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}\to &\$3500\\ r=rate\to 6\%\to (6)/(100)\to &0.06\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{quarterly, thus four} \end{array}\to &4\\ t=years\to &12 \end{cases} \\\\\\ A=3500\left(1+(0.06)/(4)\right)^(4\cdot 12)\implies A=3500(1.015)^(48)`

so, the interest earned then will be A - 3500.