Tag: implications

Questions Related to implications

Without using truth , whether
$\left[ {p\Delta \left( { \sim q\Delta r} \right)} \right]V\left[ { \sim r\Delta  \sim q\Delta p} \right] \equiv p$

  1. True

  2. False


Correct Option: B

Solve it:-
$\left( {p \to q} \right) \to [\left( { \sim p \to q} \right) \to q]$

  1. Tautology

  2. Contradiction

  3. Contingent

  4. Not statement


Correct Option: A
Explanation:
$Y=\left( p\longrightarrow q \right) \longrightarrow \left[ \left( \sim p\longrightarrow q \right) \longrightarrow q \right]$
Method : TRUTH TABLE [  ALWAYS PREFERABLE]

 $p$  $q$  $p\longrightarrow q$  $\left( \sim p\longrightarrow q \right) $  $\left[ \left( \sim p\longrightarrow q \right) \longrightarrow q \right]$  $Y$
 $1$  $0$  $0$  $1$  $1$ $1$ 
 $1$  $1$  $1$  $1$  $1$  $1$
 $0$  $0$  $1$  $0$  $1$  $1$
 $0$  $1$  $1$  $1$  $1$  $1$
As the result is always TRUE $\left(i.e. 1\right)$;
$\left( p\longrightarrow q \right)\longrightarrow \left[ \left( \sim p\longrightarrow q \right) \longrightarrow q \right]$ is Tautology.

A. Tautology



















Which of the following is true

  1. $a _{r}=a _{n-r}$

  2. $a _{2r}=a _{n-r}$

  3. $a _{r}=a _{2n-r}$

  4. $None\ of\ these$


Correct Option: A

Let $p$ and $q$ be two propositions given by
$p$ : The sky is blue.
$q$ : The milk is white.
Then $p\wedge q$ will be

  1. The sky if blue or milk is white

  2. The sky is blue and milk is white

  3. The sky is white and milk is blue

  4. If the sky is blue then milk is white


Correct Option: B
Explanation:

$p \wedge q$ means statement p and q
=> The sky is blue and  milk is white.

Let $p$ and $q$ be two propositions. Then the contrapositive the implication $p\rightarrow q$

  1. $\sim q\rightarrow \sim p$

  2. $\sim p\rightarrow \sim q$

  3. $q\rightarrow p$

  4. $p\leftrightarrow q$


Correct Option: A
Explanation:

the contrapositive of $p\to q$ is $\sim q\to \sim p$

Negation of $(\sim p\rightarrow q)$ is ________________.

  1. $\sim { p }{ \wedge }\sim q$

  2. $\sim \left( p\vee q \right) \vee \left( p\vee \left( \sim p \right) \right) $

  3. $\sim \left( p\vee q \right) \wedge \left( p\vee \left( \sim p \right) \right) $

  4. $\left( \sim p\vee q \right) \wedge \left( p\vee \sim q \right) $


Correct Option: A

$p \wedge ( q \vee \sim p ) =?$

  1. $p \vee q$

  2. $p \wedge q$

  3. $p \rightarrow  q$

  4. none of these


Correct Option: B

$( p \wedge q ) \vee ( \sim p \wedge q ) \vee ( \sim q \wedge r ) =? $

  1. $q \vee r$

  2. $q \wedge r$

  3. $q \rightarrow r$

  4. none of these


Correct Option: B

If $p$ is false, $q$ is true, then which of the following is/are false?

  1. $\sim (p\Rightarrow q)$

  2. $\sim p$

  3. $\sim p\Rightarrow q$

  4. $\sim q$


Correct Option: A,D
Explanation:
 $p$  $q$  $p\Rightarrow q$ $\sim \left( p\Rightarrow q \right) $  $\sim p$  $\sim q$   $\sim p\Rightarrow q$
 F  T  T  F  T  F  T

Here we see that $\sim \left( p\Rightarrow q \right) $  and $\sim q$  are false

$p$: He is hard working.
$q$: He is intelligent.
Then $ \sim q\Rightarrow\sim p$, represents

  1. If he is hard working, then he is not intelligent.

  2. If he is not hard working, then he is intelligent.

  3. If he is not intelligent, then he is not had working.

  4. If he is not intelligent, then he is hard working.


Correct Option: C
Explanation:

p:she is hardworking
q:she is intelligent

~p:she is not hardworking
~q:she is not intelligent

~q=>~p 
means She is not intelligent implies she is not hardworking
Hence, Option C