Unsure about question two

Mainly confused about parts d, e, and f

Question 2- The trim line at PW is a small subassembly line that, along with other such lines, feeds into the final chassis line. The entire assembly line, which consists of more than 900 workstations, is to make PW's new E cars. The trim line itself involves only 13 work elements and must handle 20 cars per hour. Work-element data are as follows: a) Draw a precedence diagram. b) What cycle time (in minutes) results in the desired output rate? c) What is the theoretical minimum number of stations? d) Use the longest work element decision rule to balance the line and calculate the efficiency of your solution. e) Use the most followers work element decision rule to balance the line and calculate the efficiency of your solution. f) Suppose that in addition to the usual precedence constraints, there are two zoning constraints within the trim line. First, work elements K and L should be assigned to the same station; both use a common component, and assigning them to the same station conserves storage space. Second, work elements H and J cannot be performed at the same station. f.1) Using trial and error, balance the line as best you can. f.2) What is the efficiency of your solution