A Project Has the Activity Duration and Cost Information Indicated

A project has the activity duration and cost information indicated in the table where all times are in weeks.What is the lowest total cost for completing this project in 33 weeks?
$$\begin{array} { | l | l | l | l | l | l| } \hline \text { Activity } & \begin{array} { l } \text { Narmal } \\\text { time }\end{array} & \begin{array} { l } \text { Crash } \\\text { time }\end{array} & \begin{array} { l } \text { Normal } \\\text { Cost }\end{array} & \begin{array} { l } \text { Crash } \\\text { Cost }\end{array} & \text { Predecessor } \\\hline \text { A } & 8 & 5 & \$ , 000 & 2,000 & \\\hline B & 6 & 4 & 1,500 & 2,000 & \text { A } \\\hline \mathrm { C } & 8 & 5 & 1,800 & 2,300 & \text { A } \\\hline \mathrm { B } & 12 & 9 & 1,000 & 1,800 & \mathrm {~B} \\\hline \mathrm { E } & 14 & 11 & 950 & 1,450 & \mathrm {~B} \\\hline \mathrm { F } & 9 & 7 & 1,500 & 1,900 & \mathrm { C } , \mathrm { D } \\\hline \mathrm { G } & 7 & 5 & 2,300 & 2,800 & \mathrm { E } , \mathrm { F } \\\hline\end{array}$$