[tex]\begin{gathered} \text{Instuctor charges \$8 for an hour.} \\ \text{For 4 hours he take \$52(including initial charge).} \\ So\text{, the charge for the 4 hours as private lesson(excluding initial charge) is } \\ \Rightarrow4\times\text{ \$8= \$32} \\ So,\text{ the initial charge is } \\ \Rightarrow\text{ \$52-\$32=\$20} \\ Thus\text{, the initial charge is \$20} \end{gathered}[/tex]
