A project manager has prepared a network for a small project. The following activities can be crashed at the indicated costs:

Activity

Predecessors

Normal duration $($days$)$

Normal cost $($$$)$

Crash duration $($days$)$

Crash cost $($$$)$

A

$-$

$2$

$1000$

$2$

$1000$

B

A

$5$

$1200$

$1$

refer to the cost$-$duration curve

C

A

$5$

$800$

$3$

$1000$

D

B$,$ C

$2$

$1000$

$2$

$1000$

E

B$,$ C

$2$

$1000$

$1$

$1100$