Best Vision is revamping its assembly lines to improve efficiency. As shown below, there are 10 steps

Question:

Best Vision is revamping its assembly lines to improve efficiency. As shown below, there are 10 steps to assembling a television set.
a. If Best needs to produce 120 televisions in a 40-hour work week, how should the line be balanced? Given that one worker is assigned to each workstation, how many workers are required to operate the line? What is the efficiency of the line?
b. If demand for televisions is reduced to 100 sets per 40-hour week, how many workers will be needed to man the line? Re-balance the line and re-calculate itsefficiency.