286) The artificial activity; which indicates that an activity following it cannot be started unless, the preceding activity is complete, is known as

287) A dummy activity

288) If E is the duration, ES and EF are die earliest start and finish times, LS and LF are latest start and finish times, then the following relation holds good

289) The difference between the time available to do the job and the time required to do the job, is known as

290) The probability distribution of activity times in PERT follows following distribution