Problem $6-18($Algo$)$

An assembly line is to be designed to operate $8\mathrm{.}5$ hours per day and supply a steady demand of $450$ units per day. Here are the tasks and their performance times:

TASK PRECEDING TASKS PERFORMANCE TIME $($SECONDS$)$ TASK PRECEDING TASKS PERFORMANCE TIME $($SECONDS$)$

a $38$ g d $28$

b $18$ h e $10$

c $28$ i f $43$

d a $23$ j g $8$

e b $21$ k h$,$i $48$

f c $13$ l j$,$k $8$