c) 2000 rods must be produced in the lathe section of the machine shop for each week. The rods produced are of 40 different types, each type being produced in its own batch. The average batch size is 30 rods. Each batch requires a setup with the average being 3.5 hours. The average cycle time is 10 min. Suppose the anticipated availability of the lathes is 90% and the expected utilisation is 90%. The expected worker efficiency during production is 95% and during setup is 90%. The defect rate for lathe machines is 5%. How many lathes are required during the week