Determine question $28$ to $31$ based on the following problem:

Consider the project with the following estimates for activity times and precedence relationships:

$\backslash$table$[[$Activity$,\backslash$table$[[$Optimistic$],[$Time$]],\backslash$table$[[$Most$],[$Likely Time$]],\backslash$table$[[$Pessimistic$],[$Time$]],\backslash$table$[[$Immediate$],[$Predecessor$($s$)]]],[$A$,3,4,5,-.],[$B$,5,7,9,-.],[$C$,2,3,10,$A$],[$D$,2,5,8,$B$],[E,1,7,7,$B$],[$F$,3,5,7,$C$,$ D$],[$G$,7,8,9,$D$,$ E$],[H,2,6,10,$F$]]$