Question

smith put some money in a saving certificate which earns 8% a year. the yearly interest in $600. how much did smith invest?

Answer 1

$~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill&\ 600\\ P=\textit{original amount deposited}\\ r=rate\to 8\%\to \frac{8}{100}\dotfill &0.08\\ t=years\dotfill &1 \end{cases} \\\\\\ 600=P(0.08)1\implies \cfrac{600}{0.08}=P\implies 7500=P$