Answer and Explanation:
Serial activities are activities that are performed one after the other. In serial activities, one step in a job is finished before the other step starts. In other words more time may be spent as against concurrent activities whereby the two steps in a job can be performed at the same time such that the second step can start while the first step of the job is in progress. Managers prefer concurrent activities because it saves time as jobs are completed faster when steps can be performed "concurrently"