A worker is assigned three tasks, A, B, and C, each having a duration of 10 days. One approach to completing these tasks would be to focus on one at a time, complete it, and then move to the second, followed by the third. One multitasking approach would call for dividing each task in half and rotating from one to the other so that the first halves of A, B, and C are completed before the second halves of A, B, and C are completed (always in this order). What is the difference in the average completion times for the multitasked activities when compared to the one at a time approach?