Problem $2$

Consider the network described in the table below.

Immediate Optimistic Likely Pessimistic

$\backslash$table$[[$Activity Predecessor$($s$),\backslash$table$[[$Time$],[($days$)]],\backslash$table$[[$Time$],[($days$)]],],[$W$,$none,$4,6,14],[$H$,$none,$7,10,13],[$C$,$W$,3,5,7],[$G$,$H$,4,6,8],[$E$,$H$,3,3,3],[$F$,$C$,$E$,1,4,10]]$

What is the probability of completing the project in $15$ days or less?