Question

After 1 year, $500 deposited in a savings account with simple interest had earned $75 in interest. What was the interest rate?

Answer 1

`~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill & \$ 75\\ P=\textit{original amount deposited}\dotfill & \$500\\ r=rate\to r\%\to (r)/(100)\\ t=years\dotfill &1 \end{cases} \\\\\\ 75 = (500)((r)/(100))(1) \implies 75=5r\implies \cfrac{75}{5}=r\implies \stackrel{ \% }{15}=r`