Question $4$: We are producing four products, A$,$ B$,$ C and D$,$ on a CNC Machine where each of these products requires one operation on this machine. Average production times $($TP$)$ are given below. The CNC machine operates AT $=40$ hours per week.

a$)$ We set the weekly production targets of products B$,$ C$,$ D to zero. Calculate the maximum weekly production target value for product A so that the Utilization will be $70\%.$

b$)$ Calculate the weekly Work Load $($hr$/$week$)$ and the Utilization $(\%)$ of the CNC Machine given that the weekly production targets of products A$,$ B$,$ C$,$ D are $24,48,60,25($part$/$week$),$ respectively.

c$)$ We set the weekly production targets of products A$,$ B$,$ C to $12,36,36,$ respectively. Calculate the maximum weekly production target value for product D so that the Utilization will be $60\%.$

d$)$ We set the weekly production targets of products A$,$ B$,$ C$,$ D all to equal to each other. Calculate the maximum weekly production target value for any of these four products so that the Utilization will be $90\%.$ Clarification: the question is not asking the sum of $4$ production targets but the quantity that all four are equal to$.$