I'm having trouble with the last part with the efficiency of obtained solution.

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 follows: Work Element Time (min) B C E F G 1.8 0.4 1.6 1.4 0.8 0.7 0.5 1.5 1.4 1.4 1 0.5 0.8 Immediate Predecessor(s) None None None B A F A H GE J D I, LK J K L F G H | J K L M 0.7 0.5 1.5 1.4 1.4 1 0.5 0.8 A F A H GE J D I, LK a. Choose the correct precedence diagram below. OA OB. c. - 1.8 1.5 1.4 1.8 1.5 1.4 1.8 1.5 1.4 ) 0.5 G0.5 0.4 0.8 0.8 M 0.8 70.7 0.5 0.4 1.4 0.8 0.4 0.8 1.4 0.8 1.6 1.4 0.5 1.6 1.4 0.5 1.6 1.4 0.5 min b. What cycle time in minutes) results in the desired output rate? 3 (Enter your response as a whole number.) car c. What is the theoretical minimum number of workstations? 5 stations (Enter your response rounded up to the next whole number.) d. Use the longest work element decision rule to balance the line and calculate the efficiency of your solution. Which work elements are assigned to each workstation? To start off, assign A to the Station 1 Work elements A, F, G should be assigned to Station 1. Work elements CD should be assigned to Station 2. Work elements H,I should be assigned to Station 3. Work elements L, B, E should be assigned to Station 4. Work element(s) JK should be assigned to Station 5. The last unassigned work element M should be assigned to Station 6. What is the efficiency of obtained solution? % (Enter your response as a percent rounded to one decimal place.)