Consider a system having m resources of the same type. These resources are shared by $3$ processes $A$,$B$, and $C$ which have peak demands of $3$, $4$ and $6$ respectively. For what value of m deadlock will not occur?
We have m resourses now suppose we have three process like below
P1,P2 and P3
Max resourses by which deadlock happen=10
So minimum resourses by which deadlock didn't happen =10+1>=11 therefore answer 13 according to option.
Condition for deadlock free
Here R= total no. Of resources
n= Max demand of resources for each process p
m >= ([1×(3-1)]+[1×(4-1)]+[1×(6-1)]) +1
m>=11 : for deadlock free
So, answer should be 13,15