The table below has question-wise data on the performance of students in an…

The table below has question-wise data on the performance of students in an examination. The marks for each question are also listed. There is no negative or partial marking in the examination.

$\begin{array}{|c|c|c|c|c|} \hline \textbf{Q No.} & \textbf{Marks} &\textbf{Answered}&\textbf{Answered}&\textbf{Not}\\&&\textbf{ Correctly} &\textbf{Wrongly} & \textbf{Attempted} \\\hline \text{1} & \text{2} &\text{21} &\text{17} &\text{6}\\\hline \text{2} & \text{3} &\text{15} & \text{27}& \text{2}\\\hline \text{3} & \text{2} &\text{23} & \text{18} & \text{3}\\\hline \end{array}$

What is the average of the marks obtained by the class in the examination?