Calculate Minimum cost of project crashing
What is the minimum cost of crashing the following project by 4 days?
Activity Normal Time (days) Crash Time
(days) Normal Cost Crash Cost Immediate Predecessor(s)
A 6 5 $ 900 $1,000 ?
B 8 6 300 400 ?
C 4 3 500 600 ?
D 5 3 900 1,200 A, B
E 8 5 1,000 1,600 C