Question

Margo borrows $1400, agreeing to pay it back with 5% annual interest after 17 months. How much interest will she pay? Round your answer to the nearest cent, if necessary.

Answer 1

well, let's keep in mind that since a year has 12 months, then 17 months is really 17/12 of a year, so

`~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\\ P=\textit{original amount deposited}\dotfill & \$1400\\ r=rate\to 5\%\to (5)/(100)\dotfill &0.05\\ t=years\dotfill &(17)/(12) \end{cases} \\\\\\ I = (1400)(0.05)((17)/(12)) \implies I \approx 99.17`