a$-$b$)$ Using Johnson's rule for $2-$machine scheduling, the sequence is:

c$)$ For the schedule developed using Johnson's rule, the total length of time taken to complete the seven printing and binding jobs $($including binding$)=$ hours $($enter your response as a whole number$).$

The following set of seven jobs is to be processed through two work centers at George Heinrich's printing company. The sequence is first printing, then binding. Processing time at each of the work centers is shown in the following table: