If anyone can break down everything, especially the activity chart with "each activity reduced by weeks" that would be helpful because I don't understand it at all. Also, how to get to the total crashing cost which is the last problem at the bottom of the problem. Thank you so much!

The following is a table of activities associated with a project at Rafay Ishfaq's software firm in Chicago, their durations, what activities each must precede and the crash cost to reduce duration per week: Precedes Duration (weeks) 3 2 4 Activity A (start) B E F (end) B, C E F Crash Cost/Week $380 $130 $240 $140 $400 1 F 4 Suppose that Rafay is only given 8 weeks (instead of 11) to complete the project. By how many weeks should each activity be crashed in order to meet the deadline? Assume that you can crash an activity down to 0 weeks duration. Activity Each Activity Should be Reduced BY (weeks) O week(s) 2 week(s) A B C 3 week(s) E O week(s) F O week(s) What is the total crashing cost? $370 (Enter your response as a whole number.)