Question

3.6.PS-8 If the simple interest on $5,000 for 9 years is $2,700, then what is the interest rate? The rate is %. .​

Answer 1

$~~~~~~ \textit{Simple Interest Earned}\\\\I = Prt\qquad\begin{cases}I=\textit{interest earned}\dotfill &\ 2700\\P=\textit{original amount deposited}\dotfill & \ 5000\\r=rate\to r\%\to \frac{r}{100}\dotfill &0.0r\\t=years\dotfill &9\end{cases}\\\\\\2700=(5000)(0.0r)(9)\implies 2700=45000(0.0r)\implies \cfrac{2700}{45000}=0.0r\\\\\\\cfrac{3}{50} = 0.0r\implies \cfrac{3}{50} = \cfrac{r}{100}\implies \cfrac{3\cdot 100}{50}=r\implies 6 = \stackrel{\%}{r}$