a.

P0  A B C D

P0   0 0 0 0

P1   0 7 5 0

P2   1 0 0 2

P3   0 0 2 0

P4   0 6 4 2

 

b.

Yes. The system is in a safe state.

We can know Available = (1, 5, 2, 0), either process P0 or P3 could run. Once process P3 runs, it releases its resources which allow all other existing processes to run.

 

c.

Yes the request can be granted immediately

(1). Request 1≤  Need1    (  (0,4,2,0) ≤(0,7,5,0 ) )

(2). Request 1≤Available1