Question

$4500 is invested at a simple interest rate of 4% per annum for 3years,3month.find the amount of interest earned.

Answer 1

now, let's keep in mind that a year has 12 months, thus 3 months is really 3/12 of a year

`~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\\ P=\textit{original amount deposited}\dotfill & \$4500\\ r=rate\to 4\%\to (4)/(100)\dotfill &0.04\\ t=years\dotfill &3 \end{cases} \\\\\\ I = (4500)(0.04)(3) \implies \boxed{I = 540} \\\\[-0.35em] ~\dotfill`

`~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\\ P=\textit{original amount deposited}\dotfill & \$4500\\ r=rate\to 4\%\to (4)/(100)\dotfill &0.04\\ t=years\to (3)/(12)\dotfill &(1)/(4) \end{cases} \\\\\\ I = (4500)(0.04)((1)/(4)) \implies \boxed{I=45}`