Consider the following features/factors:
1. Projects are of the non-repetitive type
2. Time required need not be known
3. Time required is known precisely
4. Events have been established for planning
5. Emphasis is given to activities of project
PERT is preferred for planning because of

A. 9 days B. 13 days C. 14 days D. 19 days

A. $$\frac{{{{\text{t}}_{\text{o}}} + 3{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{2}$$ B. $$\frac{{{{\text{t}}_{\text{o}}} + 3{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{3}$$ C. $$\frac{{{{\text{t}}_{\text{o}}} + 4{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{4}$$ D. $$\frac{{{{\text{t}}_{\text{o}}} + 4{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{5}$$ E. $$\frac{{{{\text{t}}_{\text{o}}} + 4{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{6}$$

A. Number of operations B. Output of labour C. Output of machinery D. All the above

A. 3.5 and $$\frac{5}{6}$$ B. 5 and $$\frac{{25}}{{36}}$$ C. 3.5 and $$\frac{{25}}{{36}}$$ D. 4 and $$\frac{5}{6}$$