The heir to the throne was due 60 days from now and the first-time father had a serious construction ...

The heir to the throne was due 60 days from now and the first-time father had a serious construction project on his hands converting his man cave into a nursery.
 
  The seven activities, their normal and expedited times (in days) and costs appear in the table. Just to be on the safe side, he decided to bring the project in at 53 days in case the delivery was a week early. Tell him what the least expensive 53-day project is; which activities should be reduced in duration, by how many days, and at the total cost, so he can roll up the sleeves on his World's Greatest Dad sweatshirt, and get to work.
 
  Activity Normal time Crash time Normal Cost Crash Cost Predecessor
  A 5 3 500 1100
  B 18 15 900 2300 A
  C 12 9 2500 3000 A
  D 9 7 500 650 B
  E 15 12 3000 5000 B
  F 12 10 4000 5000 C, D
  G 20 15 3600 4800 E, F