Here are the precedence requirements, normal and crash activity times, and normal and crash costs for a construction project:

a$.$ What are the critical path and the estimated completion time?

b$.$ To shorten the project by three weeks, which tasks would be shortened and what would the final total project cost be$?\backslash$table$[[,$Path,Activity's time,Total time $($Week$),n=0,n=1,n=2,n=3$