Estimated time required in normal conditions complete an activity is -. ?

Expected time = (P +4M + O)/6

answer is C Most likely time because while calculating grant chart or PERT the normal time means the expected time calculation for which the activity will probably complete so in normal condition it can be called even expected time = (a +4m+b)/6

Optimistic time: a

Most likely time: m=normal time also

Pessimistic time: b

(c) Most likely time 

I believe its (c) the most likely time you have given for the task to be finished give or take; at normal conditions you can estimate the time you need to finish the task in hand.....at normal conditions optimism and pessimism are not in need. Extreme conditions taken external or internal factors for a task to be completed under the pessimistic time or optimistic time is most probably something you cant control.

I would say C. 

C

Non of them it isEquation as Mr. Ayoub Tartir.

Of course i will choose #C# because when we work that's the best time in life after The worship of God..

with my regard..

(d) None of these. Estimated time = [Optimistic Time + Pessimistic Time +4 x Most Likely Time]/6

Thanks for the invitation

Well...about me  i would say the option  (C) Most likely time

Answer . d None of these 

Mean time = (Tp+To+4Tm)/6