QUESTION $19$

The estimated mean time for an activity with a most likely time $(m)$ equal to $11$ days, the optimistic time $($a$)$ equal to $6$ days, and the pessimistic time $($b$)$ equal to $18$ days is

A$.11$ days.

B$.11\mathrm{.}67$ days.

C$.9\mathrm{.}67$ days.

D$.11\mathrm{.}33$ days.