31. In industrial work study, work sampling is a technique of
32. Workmen arrive at a mine workshop to receive tools for maintenance. The inter-arrival time of workmen at the service counter is exponentially distributed with an average time of 10 min. The service time at the counter is also distributed exponentially with a mean time of 6 min. The probability that there is a queue (more than one workman) at the service counter is,
33. A mining project comprising of A, B and C activities is scheduled for 90 days at a cost of Rs. 1200 million. The manager of the project decides to reduce the time for completion of the project to 85 days. The decision was taken after 45 days, The minimum cost of the project in million rupees after crashing 5 days is
34. Which one of the following operation research problems is solved by the Branch and Bound algorithm?
35. In the project network shown activity durations are given in months. If the activity can be crashed to expedite the project, which one would you crash and by how many months?
36. The failure data of equipment follows an exponential distribution. If the mean time between failure is 3000 hours. the reliability of the equipment for 750 hours is
37. In an opencast mine loading and transporting has been carried out by shovel dumper combination. There is only one shovel is in operation. Dumpers arrive at the rate of 10 dumpers per hour and it takes shovel on an average 5 minutes to load a dumper. Assume arrival is Poisson and service time is exponentially distributed, find the expected number of dumpers waiting to be load in the system.
38. Four mines A, B, C and D are located along a road as shown with production in Mt per year 1, 2, 1 and 3 respectively. In order to handle total coal produced. the ideal distance of a coal washery along the road from the mine A in Km is
