The time estimates obtained from four contractors (P, Q, R and S) for executing a particular job are as under:
\[\begin{array}{|c|c|c|c|} \hline \textbf{Contractor} & \textbf{Optimistic time, $t_o$} & \textbf{Most likely time, $t_m$} & \textbf{Pessimistic time, $t_p$} \\ \hline \text{P} & 5 & 10 & 13 \\ \hline \text{Q} & 6 & 9 & 12 \\ \hline \text{R} & 5 & 10 & 14 \\ \hline \text{S} & 4 & 10 & 13 \\ \hline \end{array}\]
Which of these contractors is more certain about completing the job in time?
Which of the following statements (pertaining to CPM network analysis) are correct?
A. It is an event-oriented method.
B. It is an activity-oriented method.
C. Time and cost are controlling factors.
D. Time alone is the controlling factor.
Choose the most appropriate answer from the options given below:
A construction project consists of five activities. The immediate successor activity relationship and duration of each activity are mentioned.

Find the total duration of the project in weeks.
P and Q play chess frequently against each other. Of these matches, P has won 80% of the matches, drawn 15% of the matches, and lost 5% of the matches.
If they play 3 more matches, what is the probability of P winning exactly 2 of these 3 matches?
In a regular semi-circular arch of 2 m clear span, the thickness of the arch is 30 cm and the breadth of the wall is 40 cm. The total quantity of brickwork in the arch is _______ m\(^3\). (rounded off to two decimal places)
