Question

Rex took out a loan for $5000 and planned to pay it back in 4 years. If he paid $600 in interest for those 4 years, what was the simple interest rate?.

Answer 1

`~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\dotfill & \$600\\ P=\textit{original amount deposited}\dotfill & \$5000\\ r=rate\to r\%\to (r)/(100)\\ t=years\dotfill &4 \end{cases} \\\\\\ 600=5000((r)/(100))(4)\implies \cfrac{600}{5000(4)}=\cfrac{r}{100}\implies \cfrac{3}{100}=\cfrac{r}{100}\implies \boxed{3=r}`