Hence

total float = maximum time available – activity duration

                  = LFT – EST - t ^ij

                  = LST – EST

b)     Free float: - Free float is the time available to fluctuate the activity without the affecting the succeeding activity. The mean of without affecting succeeding activity is that the activity must finish before the earliest occurrence of the head event.

                              Time available = T _{E ⁱ} – EST

                              Free float = Time available – activity duration
                                              =  T _{E ⁱ} – EST - T _{E ^ij}

                              Free float = T _{E ⁱ} – EFT

c)       Independent float: - It is the time available to fluctuate if the preceding activities get completed as late as possible and succeeding activities get started as early as possible.

                              Hence time available = T _{E ⁱ} – T _Lⁱ 
This is the minimum time available to execute