please show work

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. Activity Normal Time (weeks) Crashed Time (weeks) Normal Cost Crashed Cost Predecessor(s) 5 3 $800 $1,200 B 6 5 $350 $500 6 5 $600 $725 D 3 2 $750 $900 E 6 3 $1,500 $3.300 F 5 3 $825 $1,025 B What is the duration of the project (in weeks)? Number What is the target duration of the project (after crashing the project)? Number By how many weeks should activity A be crashed? Number By how many weeks should activity B be crashed? Number By how many weeks should activity C be crashed? Number By how many weeks should activity D be crashed? Number By how many weeks should activity E be crashed? Number By how many weeks should activity F be crashed? Number 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.) Number