Complete the CPM illustrated below. Completed the forward pass, and backward pass, calculate the project duration, total floats, and the critical path activities $($if any$).$

$\backslash$table$[[,,,\backslash$table$[[$Task Duration$],[$Thours$)]]],[$A ID$,$Task Description,Task Predecessors,$],[$Project start,,$0,],[$B$,$Buy materials for A$,$A$,10],[$C$,$Buy materials for B$,$A$,20],[$D$,$Build A$,$B$,$ C$,30],[$E$,$Build B$,$B$,$ C$,20],[$F$,$Polish and finish B$,$E$,40],[$G$,$Join A and B$,$D$,$ F$,20],[$H$,$Project finish,G$,0]]$