A computer system has recently been installed in the accounts department of a manufacturing company. The activities involved in introducing the system are listed below together with their normal durations and costs. It would be possible to shorten the overall project duration by crashing certain activities at extra cost, so the relevant details are also included. In addition, there will be a weekly charge of $$7000$ to cover overheads. $($CLO$4)$ActivityPredecessorNormal Time $($weeks$)$Normal Cost $($S$)$Crash Time $($weeks$)$Crash Cost$3300027000-660006000$A$8000119000150021500$A$8400059000$F$430008000$GC$,$ D$220002000$HF$330009000$