$(25$ marks$)$

The following table shows the normal and crash costs and completion times $($in weeks$)$ for each activity in a project network.

$\backslash$table$[[$Activity$,\backslash$table$[[$Normal$],[$Time$]],\backslash$table$[[$Crash$],[$Time$]],\backslash$table$[[$Normal$],[$Cost$]],\backslash$table$[[$Crash$],[$Cost$]],\backslash$table$[[$Immediate$],[$Predecessor$]]],[$A$,6,5,2500,2700,--],[$B$,9,6,2000,2600,--],[$C$,4,3,2100,2400,$A$],[$D$,9,7,2300,3200,$B$,$ C$],[$E$,3,2,2700,2800,$C$],[$F$,5,3,1800,2600,$E$],[$G$,3,1,2500,3500,$D$,$ F$]]$

a$.$ Determine the project completion time if no activity is crashed. What would be the total cost of completing the project?