1
GATE CSE 2007
MCQ (Single Correct Answer)
+2
-0.6
Which one of these first-order logic formulae is valid?
A
$$\forall x\left( {P\left( x \right) \Rightarrow Q\left( x \right)} \right) \Rightarrow \left( {\left( {\forall xP\left( x \right)} \right) \Rightarrow \left( {\forall xQ\left( x \right)} \right)} \right)$$
B
$$\exists x\left( {P\left( x \right) \vee Q\left( x \right)} \right) \Rightarrow \left( {\left( {\exists xP\left( x \right)} \right) \Rightarrow \left( {\exists xQ\left( x \right)} \right)} \right)$$
C
$$\exists x\left( {P\left( x \right) \wedge Q\left( x \right)} \right) \Leftrightarrow \left( {\left( {\exists xP\left( x \right)} \right) \wedge \left( {\exists xQ\left( x \right)} \right)} \right)$$
D
$$\forall x\exists yP\left( {x,y} \right) \Rightarrow \exists y\forall xP\left( {x,y} \right)$$
2
GATE CSE 2007
MCQ (Single Correct Answer)
+1
-0.3
Let $$S$$ be a set6 of $$n$$ elements. The number of ordered pairs in the largest and the smallest equivalence relations on $$S$$ are
A
$$n$$ and $$n$$
B
$${n^2}\,$$ and $$n$$
C
$${n^2}\,$$ and $$0$$
D
$$n$$ and $$1$$
3
GATE CSE 2007
MCQ (Single Correct Answer)
+2
-0.6
Consider the following Hasse diagrams.
GATE CSE 2007 Discrete Mathematics - Set Theory & Algebra Question 44 English 1
GATE CSE 2007 Discrete Mathematics - Set Theory & Algebra Question 44 English 2
GATE CSE 2007 Discrete Mathematics - Set Theory & Algebra Question 44 English 3
GATE CSE 2007 Discrete Mathematics - Set Theory & Algebra Question 44 English 4

Which all of the above represent a lattice?

A
(i) and (iv) only
B
(ii) and (iii) only
C
(iii) only
D
(i), (ii) and (iv) only
4
GATE CSE 2007
MCQ (Single Correct Answer)
+1
-0.3
Suppose there are two coins. The first coin gives heads with probability 5/8 when tossed, while the second coin gives heads with probability 1/4. On e of the two coins is picked up at random with equal probability and tossed. What is the probability of obtaining heads?
A
7/8
B
$${\raise0.5ex\hbox{$\scriptstyle 1$} \kern-0.1em/\kern-0.15em \lower0.25ex\hbox{$\scriptstyle 2$}}$$
C
7/16
D
5/32