The following table provides the information necessary to construct a project network, along with project crash data.

$\backslash$table$[[$Activity$,\backslash$table$[[$Activity$],[$Predecessor$]],$Activity,Activity$],[$Time $($weeks$),$Cost $($S$)],[$Normal Crash Normal Crash$],[2,-,20,8,1000,1480],[3,-,24,20,1200,1400],[4,1,14,7,700,1190],[5,3,10,6,500,320],[5,3,11,5,550,730]]$

Under normal conditions, what is the duration of the critical path $($in weeks$)?$

Answer: