The construction network plan for a unit is given in Fig $2.$ Table $3$ gives the man sonstruct and team size for each operation. Prepare a line of balance $40$ houses using a target rate of build $4$ houses per week. Assume a minimum buffer time of week and $6-$hours day.

$($a$)$ What is the overall duration of the project?

$($b$)$ When the house number $30$ will be started?

Fig. $2-$ Network of a unit for line of balance

Table $3-$ Required man hours for line of balance programming

$\backslash$table$[[$OPERATION$,$MAN HOURS $($M$),$MEN PER OPERATION $($Q$)],[$A$,25,2],[$B$,33,3],[$C$,45,4],[$D$,36,3],[$E$,25,2],[$F$,42,4]]$