# UGC-NET | UGC NET CS 2018 Dec – II | Question 2

Suppose a system has 12 instances of some resources with n processes competing for that resource. Each process may require 4 instances of the resource. The maximum value of n for which the system never enters into deadlock is**(A)** 3**(B)** 4**(C)** 5**(D)** 6**Answer:** **(A)****Explanation:** Given,

Number of resources (R) = 12

Max need for each resource (N) = 3

Since deadlock-free condition is:

R ≥ P(N − 1) + 1

Where R is total number of resources,

P is the number of processes, and

N is the max need for each resource.

12 ≥ P(4 − 1) + 1 11 ≥ 3P 11/3 ≥ P P ≤ 3.66

(Take, floor value for maximum)

Therefore, the largest value of P that will always avoid deadlock is 3.

Option (A) is correct.

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