Question

The expected time (t_e) of a PERT activity in terms of optimistic time (t₀), pessimistic (t_p) and most likely time (t_L) is given by                                                            

      (a) $t_{e}=\frac{t_{o}+4t_{l}+t_{p}}{6}$ 

      (b) $t_{e}=\frac{t_{o}+4t_{p}+t_{L}}{6}$

      (c) $t_{e}=\frac{t_{o}+4t_{L}+t_{p}}{3}$

      (d)$t_{e}=\frac{t_{o}+4t_{p}+t_{L}}{3}$