1
GATE CSE 2018
MCQ (Single Correct Answer)
+2
-0.6
Consider the first-order logic sentence
$$\varphi \equiv \,\,\,\,\,\,\,\exists s\exists t\exists u\forall v\forall w$$ $$\forall x\forall y\psi \left( {s,t,u,v,w,x,y} \right)$$
where $$\psi $$ $$(𝑠,𝑑, 𝑒, 𝑣, 𝑀, π‘₯, 𝑦)$$ is a quantifier-free first-order logic formula using only predicate symbols, and possibly equality, but no function symbols. Suppose $$\varphi $$ has a model with a universe containing $$7$$ elements.

Which one of the following statements is necessarily true?

A
There exists at least one model of $$\varphi $$ with universe of size less than or equal to $$3.$$
B
There exists no model of $$\varphi $$ with universe of size less than or equal to $$3.$$
C
There exists no model of $$\varphi $$ with universe of size greater than $$7.$$
D
Every model of $$\varphi $$ has a universe of size equal to $$7.$$
2
GATE CSE 2018
Numerical
+1
-0
Consider a matrix $$A = u{v^T}$$ where $$u = \left( {\matrix{ 1 \cr 2 \cr } } \right),v = \left( {\matrix{ 1 \cr 1 \cr } } \right).$$ Note that $${v^T}$$ denotes the transpose of $$v.$$ The largest eigenvalue of $$A$$ is _____.
Your input ____
3
GATE CSE 2018
Numerical
+1
-0
Consider a system with $$3$$ processes that share $$4$$ instances of the same resource type. Each process can request a maximum of $$K$$ instances. Resource instances can be requested and released only one at a time. The largest value of $$K$$ that will always avoid deadlock is ____.
Your input ____
4
GATE CSE 2018
MCQ (Single Correct Answer)
+2
-0.6
In a system, there are three types of resources: $$E, F$$ and $$G.$$ Four processes $${P_0},$$ $${P_1},$$ $${P_2}$$ and $${P_3}$$ execute concurrently. At the outset, the processes have declared their maximum resource requirements using a matrix named Max as given below. For example, Max$$\left[ {{P_{2,}}F} \right]$$ is the maximum number of instances of $$F$$ that $${{P_{2,}}}$$ would require. The number of instances of the resources allocated to the various processes at any given state is given by a matrix named Allocation.

Consider a state of the system with the Allocation matrix as shown below, and in which $$3$$ instances of $$E$$ and $$3$$ instances of $$F$$ are the only resources available.

Allocation
E F G
P0 1 0 1
P1 1 1 2
P2 1 0 3
P3 2 0 0

Max
E F G
P0 4 3 1
P1 2 1 4
P2 1 3 3
P3 5 4 1

From the perspective of deadlock avoidance, which one of the following is true?

A
The system is in $$safe$$ state.
B
The system is not in $$safe$$ state, but would be $$safe$$ if one more instance of $$E$$ were available
C
The system is not in $$safe$$ state, but would be $$safe$$ if one more instance of $$F$$ were available
D
The system is not in $$safe$$ state, but would be $$safe$$ if one more instance of $$G$$ were available