Following information pertain to a maintenance project$-($Duration in days$)$:

$\backslash$table$[[$Normal$,$Crash,Normal,Crash,$],[$Activity$,$Nuration,Duration,Cost $($Rs$.),$Cost $($RS$)],[1-2,10,7,400,640],[1-3,19,11,600,1160],[2-3,10,8,500,600],[2-4,19,15,700,1000],[3-4,10,4,300,810]]$

$($i$)$ Draw the network. What is the normal duration of the project?

$($ii$)$ Crash the network by $2$ days.

$($iii$)$ Calculate the normal & crashed costs of the project.

$(22)$