Use the following information to answer the given question
\(\begin{array}{c|c} & ₦ \\ \hline \text{Balance as per cash book} & 18,000\\ \text{Dishonored cheques} & 1,200 \\ \text{Bank charged} & 300 \\ \text{Unpresented cheques} & 2,400\end{array}\)
The adjusted cash book balance is