19. On average, it takes passengers 40 seconds to prepare for the line, and to place all carry on items in the trays for the X-ray scanner. The X-ray scanner takes 50 seconds per tray, and the average passenger utilizes 2 trays. The screening station requires 40 seconds per person. Finally, retrieving of belongings takes 65 seconds. All the times mentioned represent activity time at the various activities and do not include the effect of waiting. Calculate the theoretical flow time of the security check process