The following table gives data on normal time and cost and crash time and cost for a project:

$\backslash$table$[[$Activity$,$Normal,Crash$],[$Time$($days$),$Cost$($Tk$.),$Time$($days$),$Cost$($Tk$.)],[1-2,6,60,4,100],[1-3,4,60,2,200],[2-4,5,50,3,150],[2-5,3,45,1,65],[3-4,6,90,4,200],[4-6,8,80,4,300],[5-6,4,40,2,100],[6-7,3,45,2,80]]$

$($i$)$ Draw the network for the project

$($ii$)$ Find the critical path

$($iii$)$ Determine minimum total time and corresponding cost.