well, if take a year to be 365 days so hmmm 150 days is really just 150/365 of a year, so let's use that.
[tex]~~~~~~ \textit{Simple Interest Earned Amount} \\\\ A=P(1+rt)\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill & \$11000\\ r=rate\to 9\%\to \frac{9}{100}\dotfill &0.09\\ t=years\to \frac{150}{365}\dotfill &\frac{30}{73} \end{cases} \\\\\\ A=11000[1+(0.09)(\frac{30}{73})]\implies A=11000\left( \frac{757}{730} \right)\implies A\approx 11406.85[/tex]