Question

Find the interest due on $1,400 at 9% for 270 days. (Remember that for bank interest purposes, a year is considered to have 360 days.)
a) 93.89
b) 93.22
c) 94.50

Answer 1

since for the bank purposes, there are 360 days in a year, then 270 days is 270/360 years, or namely 3/4 years.

$\bf ~~~~~~ \textit{Simple Interest Earned} \\\\ I = Prt\qquad \begin{cases} I=\textit{interest earned}\\ P=\textit{original amount deposited}\dotfill & \ 1400\\ r=rate\to 9\%\to \frac{9}{100}\dotfill &0.09\\ t=years\to \frac{270}{360}\dotfill &\frac{3}{4} \end{cases} \\\\\\ I=(1400)(0.09)\left(\frac{3}{4} \right)\implies I=94.5$