Questions

Round-robin (RR) is one of the algorithms employed by process and network schedulers in computing. It falls under the category of Preemptive scheduling. In computing, the running task is interrupted for some time without requiring its cooperation and resumed later when the priority task has finished its execution. This is called preemptive scheduling. 

Owl

Vapour of carbon tetra chloride ccl4 is non-inflammable and is heavier than air. Hence it is used as a fire extinguisher under the trade name of pyrene.

 It can be possible in only B.C. i.e, Before Christ. That was about 2000 years ago.

 Given, 

 In 1990 B.C = 2000 + 1990 = 3990 years ago, a person is 15 years Old  

=> In 1995 B.C = 2000 + 1995 = 3995 years ago, the same person will be 10 years Old 

Therefore, In 2000 B.C = 2000 + 2000 = 4000 years ago, the same person will be 5 years Old.