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

For the schedule developed using Johnson's rule, the total length of time taken to complete the six

jobs $($including the $2$nd operation$)=$ hours $($enter your response as a whole number$).$

Six jobs are to be processed through a two$-$step operation. The first operation

involves sanding, and the second involves painting. Processing times are as follows: