operating system

Question

Consider the processes P₁, P₂, P₃, P₄ whose arrival times are 0, 1, 2, 3 and Burst times are 5, 2, 13, 7. If the Context Switching time is 1 unit (ms), what is the average waiting time if Shortest Job Next scheduling algorithm is used?

(a) 7.5	(b) 6.25
(c) 6.5	(d) None

Answer 1

this the rough solution

Answer 2

So, answer is option (B)

Answer 3

done ,no need to answer .correct answer is c.