ProjectTest Bankis composed of activities we will refer to as A, B, C, and D for convenience (and lack of creativity). Durations and precedence requirements are shown in the table. Each of these activities can be conveniently laddered into two sub-activities of equal duration. The first half of each activity serves as the predecessor to its second halfandthe first half of the original following activity. What is the expected completion time of the laddered project?

Activity Length Predecessor A 10 -- B 18 A C 14 A D 20 B, C