Question $21(1$ point$)$

A production process is shown in the figure above. The drilling operation occurs separately from, and simultaneously with the sawing and sanding operations. Welding starts when both drilling and sanding operations have been completed. After welding, a product needs to go through only one of the three assembly operations $($the operations are in parallel, where parallel lines perform the exact same operation$).$ Considering the process times at stations, what is the process time of the system $($in min$/$unit$)?$