Consider an IT development project network given below

The systems analyst has made estimates of the optimistic, most probable, and pessimistic times $($in days$)$ for these activities as follows:

Activity Optimistic Most Probable Pessimistic

$\backslash$table$[[$A$,5,6,7],[$B$,5,12,13],[$C$,6,8,10],[$D$,4,10,10],[$E$,5,6,13],[$F$,7,7,10],[$G$,4,7,10]]$

How much slack time, if any, is there for activity C$?$

Determine the expected project completion time and the variance:

Find the probability that the project will he completed in $30$ days or less: