Given the following task time estimates $($HOURS$),$TaskTimePredecessorA$40$B$20$C$25$AD$19$A$,$ BE$25$C$,$ DF$24$EG$18$Fa$.$ How long is the project length? $.$b$.$ What tasks form the critical path? c$.$ What is the LS$/$LF for activity D$.?.$d$.$ How much slack is there in activity C$?$ How much slack in activity D$?$ e$.$ What if activity D$.$ was delayed by $7$ hours, what would be the project length and critical path? f$.$ Referring to letter e$.,$ how much slack would be in activity B$.?$