Correct Answer - Option 3 : independent float
Explanation:
Float:
(i) It is associated with activity times.
(ii) It is analogous to the slack of events in PERT.
(iii) It is the range within which the start or finish time of activity may fluctuate without affecting the project completion time.
(iv) Floats are of the following types:
1. Total float: The time span by which starting or finishing of an activity can be delayed without delaying the completion of the project. Total float of activity affects total float of succeeding as well as preceding activities.
2. Free float: The delay can be made without delaying succeeding activities. It affects only preceding activities.
3. Independent Float: It is the minimum excess available time which exists without affecting any of succeeding or preceding activities.
4. Interfering Float: It is similar to head event slack.