Questions · Page 3 of 3

MCQ

MCQ 1012 Marks
Which of the following is always true?
  • A
    $\sim(p \rightarrow q) \equiv \sim q \rightarrow \sim p$
  • B
    $\sim(p \vee q) \equiv p \vee \sim q$
  • $\sim(p \rightarrow q) \equiv p \wedge \sim q$
  • D
    $\sim(p \vee q) \equiv \sim p \vee \sim q$
Answer
Correct option: C.
$\sim(p \rightarrow q) \equiv p \wedge \sim q$
(C)
$\begin{array}{l} p \rightarrow q \equiv \sim p \vee q \\ \therefore \quad \sim(p \rightarrow q) \equiv p \wedge \sim q\end{array}$
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MCQ 1022 Marks
The negation of $q \vee \sim(p \wedge \tau)$ is
  • A
    $\sim q \wedge \sim(p \vee r)$
  • $\sim q \wedge(p \wedge r)$
  • C
    $\sim q \vee(p \wedge r)$
  • D
    $\sim q \vee(p \wedge r)$
Answer
Correct option: B.
$\sim q \wedge(p \wedge r)$
(B)
$\begin{aligned} \sim[ q \vee \sim( p \wedge r )] & \equiv \sim q \wedge \sim(\sim( p \wedge r )) \\ & \equiv \sim q \wedge( p \wedge r )\end{aligned}$
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MCQ 1032 Marks
∼(p↔q) is equivalent to
  • $(p \wedge \sim q) \vee(q \wedge \sim p)$
  • B
    $(p \vee-q) \wedge(q \vee \sim p)$
  • C
    $(p \rightarrow q) \wedge(q \rightarrow p)$
  • D
    $(q \rightarrow p) \vee(p \rightarrow q)$
Answer
Correct option: A.
$(p \wedge \sim q) \vee(q \wedge \sim p)$
(A)
We know that,
$p \leftrightarrow q \equiv(p \rightarrow q) \wedge(q \rightarrow p)$
$\therefore \quad \sim(p \leftrightarrow q) \equiv \sim[(p \rightarrow q) \wedge(q \rightarrow p)]$
$\equiv \sim(p \rightarrow q) \vee \sim(q \rightarrow p)…[By Demorgan's Law]$
$\begin{aligned} \equiv(p \wedge \sim q) & \vee(q \wedge \sim p) \\ & \quad \ldots[\because \sim(p \rightarrow q) \equiv p \wedge \sim q]\end{aligned}$
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MCQ 1042 Marks
Negation of the statement: '$\sqrt{5}$ is an integer or 5 is irrational' is
  • A
    $\sqrt{5}$is not an integer or 5 is not irrational
  • B
    $\sqrt{5}$is irrational or 5 is an integer
  • C
    $\sqrt{5}$is an integer and 5 is irrational
  • $\sqrt{5}$is not an integer and 5 is not irrational
Answer
Correct option: D.
$\sqrt{5}$is not an integer and 5 is not irrational
(D)
$p : \sqrt{5}$ is an integer
q : 5 is irrational
$\sim(p \vee q) \equiv \sim p \wedge \sim q$
∴ Option (D) is correct.
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MCQ 1052 Marks
The negation of the statement
"I like Mathematics and English" is
  • A
    I do not like Mathematics and do not like English
  • B
    I like Mathematics but do not like English
  • C
    I do not like Mathematics but like English
  • Either I do not like Mathematics or do not like English
Answer
Correct option: D.
Either I do not like Mathematics or do not like English
(D)
p : I like Mathematics
q : I like English.
$\sim(p \wedge q) \equiv \sim p \vee \sim q$
∴ Option (D) is correct.
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MCQ 1062 Marks
The negation of $(p \vee \sim q) \wedge q$ is
  • A
    $(\sim p \vee q) \wedge \sim q$
  • B
    $(p \wedge \sim q) \vee q$
  • $(\sim p \wedge q) \vee \sim q$
  • D
    $(p \wedge \sim q) \vee \sim q$
Answer
Correct option: C.
$(\sim p \wedge q) \vee \sim q$
(C)
$\sim[( p \vee \sim q ) \wedge q ]$
$\equiv \sim(p \vee \sim q) \vee \sim q \quad \ldots .[$ De Morgan’s Law]
$\equiv(\sim p \wedge q ) \vee \sim q$
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MCQ 1072 Marks
Dual of the statement $(p \wedge q) \vee \neg q \equiv p \vee \neg q$ is
  • A
    $(p \vee q) \vee \sim q \equiv p \vee \sim q$
  • B
    $(p \wedge q) \wedge \sim q \equiv p \wedge \sim q$
  • $(p \vee q) \wedge \sim q \equiv p \wedge \sim q$
  • D
    $(\sim p \vee \sim q) \wedge q \equiv \sim p \wedge q$
Answer
Correct option: C.
$(p \vee q) \wedge \sim q \equiv p \wedge \sim q$
C
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MCQ 1082 Marks
The dual of the statement "Manoj has the job but he is not happy" is
  • Manoj has the job or he is not happy.
  • B
    Manoj has the job and he is not happy.
  • C
    Manoj has the job and he is happy.
  • D
    Manoj does not have the job and he is happy.
Answer
Correct option: A.
Manoj has the job or he is not happy.
(A)
p: Manoj has the job, q: he is not happy
The dual of $p \wedge q$ is $p \vee q$.
i.e., Manoj has the job or he is not happy.
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MCQ 1092 Marks
Using quantifiers $\forall, \exists$, convert the following open statement into true statement.
$' x+5-8, x \in N^{\prime}$
  • A
    $\forall x \in N, x+5=8$
  • B
    For every$x \in N, x+5>8$
  • $\exists x \in N$, such that $x+5=8$
  • D
    For every$x \in \mathrm{~N}, x+5<8$
Answer
Correct option: C.
$\exists x \in N$, such that $x+5=8$
(C)
Option (C) is a true statement, since $x=3 \in N$ satisfies $x+5=8$.
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MCQ 1102 Marks
Using quantifier the open sentence '$x^2-4=32$' defined on W in converted into true statement as
  • A
    $\forall x \in W, x^2-4=32$
  • B
    $\exists x \in W$, such that $x^2-4 \leq 32$
  • C
    $\forall x \in W, x^2-4>32$
  • $\exists x \in W$, such that $x^2-4=32$
Answer
Correct option: D.
$\exists x \in W$, such that $x^2-4=32$
(D)
Option (D) is the required true statement, since $x=6 \in W$ satisfies $x^2-4=32$
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MCQ 1112 Marks
The proposition $p \rightarrow \sim(p\wedge \sim q)$ is a
  • A
    contradiction
  • B
    tautology
  • contingency
  • D
    none of these
Answer
Correct option: C.
contingency
(C)
pq∼q$p \wedge \sim q$$\sim( p \wedge \sim q )$$p \rightarrow \sim( p \wedge \sim q )$
TTFFTT
TFTTFF
FTFFTT
FFTFTT
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MCQ 1122 Marks
The proposition $(p \rightarrow \sim p) \wedge(\sim p \rightarrow p)$ is a
  • A
    Neither tautology nor contradiction
  • B
    Tautology
  • C
    Tautology and contradiction
  • Contradiction
Answer
Correct option: D.
Contradiction
(D)
p∼p$p \rightarrow \sim p$$\sim p \rightarrow p$$(p \rightarrow \sim p) \wedge(\sim p \rightarrow p)$
TFFTF
FTTFF
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MCQ 1132 Marks
The proposition $(p \wedge q) \wedge(p \rightarrow\sim q$) is
  • Contradiction
  • B
    Tautology
  • C
    Contingency
  • D
    Tautology and Contradiction
Answer
Correct option: A.
Contradiction
(A)
pq∼q$p \wedge q$$p \rightarrow \sim q$$( p \wedge q )\wedge( p \rightarrow \sim q )$
TTFTFF
TFTFTF
FTFFTF
FFTFTF
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MCQ 1142 Marks
The statement $(p \wedge q) \rightarrow p$ is
  • A
    a contradiction
  • a tautology
  • C
    either (A) or (B)
  • D
    a contingency
Answer
Correct option: B.
a tautology
(B)
pq$p \wedge q$$(p \wedge q) \rightarrow p$
TTTT
TFFT
FTFT
FFFT
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MCQ 1152 Marks
When the compound statement is true for all its components then the statement is called
  • A
    negation statement
  • tautology statement.
  • C
    contradiction statement.
  • D
    contingency statement.
Answer
Correct option: B.
tautology statement.
B
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MCQ 1162 Marks
$(p \wedge \sim q) \wedge(\sim p \wedge q)$ is a
  • A
    Tautology
  • Contradiction
  • C
    Tautology and contradiction
  • D
    Contingency
Answer
Correct option: B.
Contradiction
(B) $(p \wedge \sim q) \wedge(\sim p \wedge q)$
$\equiv(p \wedge \sim p) \wedge(\sim q \wedge q) \ldots$...[Associative and commutative law]
$\equiv F \wedge F$...[Complement law]
$= F$
∴ Given statement is contradiction.
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MCQ 1172 Marks
The logically equivalent statement of $(p \wedge q) \vee(p \wedge r)$ is
  • A
    $p \vee(q \wedge r)$
  • B
    $q \vee(p \wedge r)$
  • $p \wedge(q \vee r)$
  • D
    $q \wedge(p \vee r)$
Answer
Correct option: C.
$p \wedge(q \vee r)$
( C )
Distributive law
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MCQ 1182 Marks
The statement, 'If it is raining then I will go to college' is equivalent to
  • A
    If it is not raining then I will not go to college.
  • If I do not go to college, then it is not raining
  • C
    If I go to college then it is raining.
  • D
    Going to college depends on my mood
Answer
Correct option: B.
If I do not go to college, then it is not raining
(B)
$r$ : It is raining, $c$ : I will go to college.
The given statement is $r \rightarrow c \equiv \sim c \rightarrow \sim r$
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MCQ 1192 Marks
The logically equivalent statement of p↔q is
  • A
    $(p \wedge q) \vee(q \rightarrow p)$
  • B
    $(p \wedge q) \rightarrow(p \vee q)$
  • $(p \rightarrow q) \wedge(q \rightarrow p)$
  • D
    $(p \wedge q) \vee(p \wedge q)$
Answer
Correct option: C.
$(p \rightarrow q) \wedge(q \rightarrow p)$
C
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MCQ 1202 Marks
Every conditional statement is equivalent to
  • its contrapositive
  • B
    its inverse
  • C
    its converse
  • D
    only itself
Answer
Correct option: A.
its contrapositive
A
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MCQ 1212 Marks
The statement p→(∼q) is equivalent to
Answer
Correct option: B.
$\sim q \vee \sim p$
(B)
$\begin{aligned} p \rightarrow(\sim q ) & =\sim p \vee \sim q \\ & \equiv \sim q \vee \sim p \end{aligned}$
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MCQ 1222 Marks
If p and q are two logical statements and A and B are two sets, then p →q corresponds to
  • $A \subseteq B$
  • B
    $A \cap B$
  • C
    $A \cup B$
  • D
    $\mathrm{A} \nsubseteq \mathrm{B}$
Answer
Correct option: A.
$A \subseteq B$
A
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MCQ 1232 Marks
The logical statement matrix ' $p \wedge q$ ' matrix can be related to the set theory's concept of
  • A
    union of two sets
  • intersection of two set
  • C
    subset of a set
  • D
    equality of two sets
Answer
Correct option: B.
intersection of two set
B
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MCQ 1242 Marks
Negation of a statement in logic corresponds to_________ in set theory.
  • A
    empty set
  • B
    null set
  • complement of a set
  • D
    universal set
Answer
Correct option: C.
complement of a set
C
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MCQ 1252 Marks
If p: Sita gets promotion,
q: Sita is transferred to Pune.
The verbal form of ∼p↔q is written as
  • A
    Sita gets promotion and Sita gets transferred to Pune
  • B
    Sita does not get promotion then Sita will be transferred to Pune.
  • C
    Sita gets promotion if Sita is transferred to Pune.
  • Sita does not get promotion if and only if Sita is transferred to Pune.
Answer
Correct option: D.
Sita does not get promotion if and only if Sita is transferred to Pune.
(D)
$\sim$ p: Sita does not get promotion and ' ↔' symbol indicates 'if and only if'.
i.e., Sita does not get promotion if and only if Sita is transferred to Pune.
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MCQ 1262 Marks
The contrapositive of the statement: "If a child concentrates then he learns" is
  • A
    If a child does not concentrate he does not learn.
  • If a child does not learn then he does not concentrate.
  • C
    If a child practises then he learns
  • D
    If a child concentrates, he does not forget
Answer
Correct option: B.
If a child does not learn then he does not concentrate.
(B)
Let p : A child concentrates
q : A child learns
Contrapositive of $p \rightarrow q$ is $\sim q \rightarrow \sim p$.
i.e., If a child does not learn then he does not concentrate
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MCQ 1272 Marks
The inverse of the statement "If you access the internet, then you have to pay the charges", is
  • If you do not access the internet, then you do not have to pay the charges.
  • B
    If you pay the charges, then you accessed the internet.
  • C
    If you do not pay the charges, then you do not access the internet.
  • D
    You have to pay the charges if and only if you access the internet
Answer
Correct option: A.
If you do not access the internet, then you do not have to pay the charges.
(A)
Let $p$ : You access the internet
q : You have to pay the charges
Inverse of $p \rightarrow q$ is $\sim p \rightarrow \sim q$
i.e., If you do not access the internet then you do not have to pay the charges.
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MCQ 1282 Marks
If Ram secures 100 marks in maths, then he will get a mobile. The converse is
  • A
    If Ram gets a mobile, then he will not secure 100 marks in maths.
  • B
    If Ram does not get a mobile, then he will secure 100 marks in maths.
  • If Ram will get a mobile, then he secures 100 marks in maths.
  • D
    None of these
Answer
Correct option: C.
If Ram will get a mobile, then he secures 100 marks in maths.
(C)
Let $p :$ Ram secures 100 marks in maths
q : Ram will get a mobile
Converse of $p \rightarrow q$ is $q \rightarrow p$
i.e., If Ram will get a mobile, then he secures 100 marks in maths.
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MCQ 1292 Marks
The converse of the statement "If x > y then x + a > y + a'' , is
  • A
    If x < y then x + a < y + a
  • If x + a > y + a then x > y
  • C
    If x < y then x + a > y + a
  • D
    If x > y then x + a < y + a
Answer
Correct option: B.
If x + a > y + a then x > y
(B)
Let p : x > y
q : x + a > y + a
Converse of $p \rightarrow q$ is $q \rightarrow p$
i.e., If $x+ a >y+ a$, then $x>y$
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MCQ 1302 Marks
The statement "If $x^2$ is not even then x is not even", is the converse of the statement
  • A
    If$x^2$is odd, then x is even
  • Ifx is not even, then $x^2$is not even
  • C
    If x is even, then $x^2$is even
  • D
    If x is odd, then $x^2$is even
Answer
Correct option: B.
Ifx is not even, then $x^2$is not even
(B)
Let $p : x^2$ is not even,
q : $x$ is not even
Converse of $p \rightarrow q$ is $q \rightarrow p$
i.e., If $x$ is not even then $x^2$ is not even
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MCQ 1312 Marks
If m: Rimi likes calculus.
n: Rimi opts for engineering branch.
Then the verbal form of m →n is
  • A
    If Rimi opts for engineering branch then she likes calculus.
  • B
    If Rimi likes calculus then she does not opt for engineering branch.
  • If Rimi likes calculus then she opts for engineering branch
  • D
    If Rimi likes engineering branch then she opts for calculus.
Answer
Correct option: C.
If Rimi likes calculus then she opts for engineering branch
(C)
' $m \rightarrow n$ ' means 'If $m$ then $n$ ',
$\therefore$ option (C) is correct.
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MCQ 1322 Marks
Assuming the first part of cach statement as p. second as q and the third as r, the statement 'if A, B,C are three distinet points, then either they are collinear or they form a triangle' in symbolic form is
  • A
    $p \leftrightarrow(q \vee r)$
  • B
    $(p \wedge q) \rightarrow r$
  • $p \rightarrow(q \vee r)$
  • D
    $p \rightarrow(q \wedge r)$
Answer
Correct option: C.
$p \rightarrow(q \vee r)$
(C)
$p : A , B , C$, are distinct points
q : Points are collinear
r : Points form a triangle
$\therefore \quad p$ implies $( q$ or r $)$, i.e., $p \rightarrow( q \vee r )$
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MCQ 1332 Marks
A compound statement p →q is false only when
  • p is true and q is false.
  • B
    p is false but q is true.
  • C
    atleast one of p or q is false.
  • D
    both pand q are false.
Answer
Correct option: A.
p is true and q is false.
A
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MCQ 1342 Marks
If a: Vijay becomes a doctor,
b: Ajay is an engineer.
Then the statement 'Vijay becomes a doctor if and only if Ajay is an engineer' can be written in symbolic form as
  • A
    $\mathrm{b} \leftrightarrow \sim \mathrm{a}$
  • $a \leftrightarrow b$
  • C
    $a \rightarrow b$
  • D
    $\mathrm{b} \rightarrow \mathrm{a}$
Answer
Correct option: B.
$a \leftrightarrow b$
(B)
"if and only if" is expressed as ' ↔'
∴ symbolic form is $a \leftrightarrow b$.
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MCQ 1352 Marks
If d: driver is drunk, a: driver meets with an accident, translate the statement 'If the Driver is not drunk, then he cannot meet with an accident' into symbols
  • A
    $\sim \mathrm{a} \rightarrow \sim \mathrm{d}$
  • $\sim \mathrm{d} \rightarrow \sim \mathrm{a}$
  • C
    $\sim d \wedge a$
  • D
    $a \wedge \sim d$
Answer
Correct option: B.
$\sim \mathrm{d} \rightarrow \sim \mathrm{a}$
(B)
( $\sim d$ : Driver is not drunk) implies
( $\sim a$ : He cannot meet with an accident).
"Implies" is expressed as ' → '.
$\therefore$ symbolic form is $\sim d \rightarrow \sim$ a
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MCQ 1362 Marks
If p: Prakash passes the exam,
q: Papa will give him a bicycle.
Then the statement 'Prakash passing the exam, implies that his papa will give him a bicycle can be symbolically written as
  • p→ q
  • B
    $p \leftrightarrow q$
  • C
    p ∧ q
  • D
    p ∨ q
Answer
Correct option: A.
p→ q
(A)
"Implies" is expressed as ' → '.
∴ symbolic form is $p \rightarrow q$
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MCQ 1372 Marks
For the statements p and q 'p →q' is read as 'if p then q'. Here, the statement q is called
  • A
    antecedent
  • consequent
  • C
    logical connective.
  • D
    prime component.
Answer
Correct option: B.
consequent
B
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MCQ 1382 Marks
A compound statement p and q is true only when
  • A
    p is true.
  • B
    q is true.
  • both p and q are true.
  • D
    none of p and q is true.
Answer
Correct option: C.
both p and q are true.
C
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MCQ 1392 Marks
A compound statement p or q is false only when
  • A
    p is false.
  • B
    q is false.
  • both p and q are false.
  • D
    depends on p and q.
Answer
Correct option: C.
both p and q are false.
C
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MCQ 1402 Marks
If p: Ram is lazy, q: Ram fails in the examination then the verbal form of ~p∨~q is
  • A
    Ram is not lazy and he fails in the examination
  • Ram is not lazy or he does not fail in the examination.
  • C
    Ram is lazy or he does not fail in the examination.
  • D
    Ram is not lazy and he does not fail in the examination.
Answer
Correct option: B.
Ram is not lazy or he does not fail in the examination.
(B) $\sim p$ : Ram is not lazy, $\sim q$ : Ram does not fail in the examination, 'v' indicates 'or'.
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MCQ 1412 Marks
Write verbally ∼p∨q where
p: She is beautiful; q: She is clever
  • A
    She is beautiful but not clever
  • She is not beautiful or she is clever
  • C
    She is not beautiful or she is not clever
  • D
    She is beautiful and clever.
Answer
Correct option: B.
She is not beautiful or she is clever
(B) $\sim p$ : She is not beautiful, ' v ' indicates 'or'.
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MCQ 1422 Marks
Let p be the proposition : Mathematics is interesting and let q be the proposition : Mathematics is difficult, then the symbol p^q means
  • A
    Mathematics is interesting implies that Mathematics is difficult
  • B
    Mathematics is interesting implies and is implied by Mathematics is difficult.
  • Mathematics is interesting and Mathematics is difficult.
  • D
    Mathematics is interesting or Mathematics is difficult.
Answer
Correct option: C.
Mathematics is interesting and Mathematics is difficult.
C
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MCQ 1432 Marks
Assuming the first part of the statement as p, second as q and the third as r, the statement 'Candidates are present, and voters are ready to vote but no ballot papers' in symbolic form is
  • A
    $(p \vee q) \wedge \sim r$
  • B
    $(p \wedge \sim q) \wedge r$
  • C
    $(\sim p \wedge q) \wedge \sim r$
  • $(p \wedge q) \wedge \sim r$
Answer
Correct option: D.
$(p \wedge q) \wedge \sim r$
(D)
$p :$ Candidates are present,
q : Voters are ready to vote
r : Ballot papers ⇒ $\sim$ r : no Ballot papers 'and' and 'but' are represented by ' $\wedge$ ' symbol.
$\therefore \quad(p \wedge q) \wedge \sim r$
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MCQ 1442 Marks
If p: Rohit is tall, q: Rohit is handsome, then the statement 'Rohit is tall or he is short and handsome' can be written symbolically as
  • $p \vee(\sim p \wedge q)$
  • B
    $p \wedge(\sim p \vee q)$
  • C
    $p \vee(p \wedge \sim q)$
  • D
    $\sim p \wedge(\sim p \wedge \sim q)$
Answer
Correct option: A.
$p \vee(\sim p \wedge q)$
(A)
p : Rohit is tall,
$\sim p$ : Rohit is short,
q : Rohit is handome,
'or' is expressed by ' $\vee$ ' symbol,
'and' is expressed by ' $\wedge$ ' symbol.
$ \therefore \quad p \vee(\sim p \wedge q)$
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MCQ 1452 Marks
If p: The sun has set, q: The moon has risen, then symbolically the statement 'The sun has not set or the moon has not risen' is written as
Answer
Correct option: D.
(D)
$\sim p$ : The sun has not set,
$\sim q$ : The moon has not risen,
'or' is expressed by ' $\vee$ ' symbol.
$ \therefore \quad \sim p \vee \sim q$
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MCQ 1462 Marks
p: There are clouds in the sky and q: it is not raining. The symbolic form is
Answer
Correct option: C.
p^∼q
(C)
p : There are clouds in the sky,
$\sim q$ : It is not raining,
'and' is expressed by ' $\wedge$ ' symbol.
$\therefore \quad p \wedge \sim q$
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MCQ 1472 Marks
Which of the following is a statement in logic?
  • A
    What a wonderful day!
  • B
    Shut up!
  • C
    What are you doing?
  • Bombay is the capital of India.
Answer
Correct option: D.
Bombay is the capital of India.
(D)
'Bombay is the capital of India' is a statement. The other options are exclamatory and interrogative sentences.
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MCQ 1482 Marks
Which of the following is a statement in logic?
  • A
    Go away
  • B
    How beautiful!
  • C
    x > 5
  • 2=3
Answer
Correct option: D.
2=3
(D)
Even though 2 = 3 is false, it is a statement in logic with truth value F.
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MCQ - Page 3 - Maths STD 12 Questions - Vidyadip