In the circuit given below, five resistances of \(10 \Omega\), \(40 \Omega\), \(20 \Omega\), \(30 \Omega\), and \(60 \Omega\) are connected as shown to a battery of 18 volts.
Total current flowing in the circuit

Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]