The Average Flow Time for the Jobs Listed in the Following

Multiple Choice

The average flow time for the jobs listed in the following table under the shortest processing time (SPT) rule is ______. $$\begin{array} { | c | c | c | } \hline \text { Job } & \begin{array} { c } \text { Processing time } \\\text { (in days\} }\end{array} & \begin{array} { c } \text { Due date (in days from } \\\text { to day's date\} }\end{array} \\\hline \text { A } & 4 & 9 \\\hline \text { B } & 10 & 18 \\\hline \text { C } & 6 & 6 \\\hline \text { D } & 12 & 19 \\\hline \text { E } & 7 & 17 \\\hline\end{array}$$

A) 18 days
B) 20 days
C) 18.8 days
D) 19.4 days