PM$.61$ Rob Smith is managing a small project at Boston University. He is under pressure to shorten the overall duration of the project by $4$ weeks and he wants to do so at the lowest cost possible. In order to meet this objective a number of activities must be crashed.

$\backslash$table$[[$Activity$,$Normal Time $($weeks$),$Crashed Time $($weeks$),$Normal Cost,Crashed Cost,Predecessor$($s$)],[$A$,6,5,$$$900,$$$1,300,],[$B$,5,3,$$$300,$$$600,-],[$C$,6,5,$$$550,$$$725,-],[$D$,5,3,$$$950,$$$1,250,$A$],[$E$,6,3,$$$1,200,$$$2,550,$C$],[$F$,3,2,$$$750,$$$950,$B$]]$

What is the duration of the project $($in weeks$)?$

What is the target duration of the project $($after crashing the project$)?$

By how many weeks should activity A be crashed?

b

By how many weeks should activity $B$ be crashed?

By how many weeks should activity $C$ be crashed?

By how many weeks should activity $D$ be crashed?

By how many weeks should activity $E$ be crashed?

By how many weeks should activity $F$ be crashed?

What is the total cost of crashing the project $4$ weeks $($just the additional cost, not total project cost$)?($Display your answer to two decimal places.$)$