a.

Need

_____________________

A B C D

0 0 0 0

0 7 5 0

1 0 0 2

0 0 2 0

0 6 4 2

 

1. The system is in a safe state, the sequence is P0->P2->P3->P4->P1


2. the request can be granted immediately. Because Needed for P0 is also enough to execute.