16
Subjective
Using contrapositive method prove that, if $n^2$ is an even integer, then $n$ is also an even integer.
Explanation
Let $p: n^2$ is an even integer.
$q: n$ is also an even integer.
Let $\sim p$ is true i.e., $n$ is not an even integer.
$\Rightarrow n^2$ is not an even integer. $\quad$ [since, square of an odd integer is odd]
$\Rightarrow \sim p$ is true.
Therefore, $\sim q$ is true $\Rightarrow \sim p$ is true.
Hence proved.
17
MCQ (Single Correct Answer)
Which of the following is a statement?
A
$x$ is a real number
B
Switch off the fan
C
6 is a natural number
D
Let me go
18
MCQ (Single Correct Answer)
Which of the following is not a statement.
A
Smoking is injurious to health
B
$2+2=4$
C
2 is the only even prime number
D
Come here
19
MCQ (Single Correct Answer)
The connective in the statement ' $2+7>9$ or $2+7<9$ ' is
A
and
B
or
C
$>$
D
$<$
20
MCQ (Single Correct Answer)
The connective in the statement "Earth revolves round the Sun and Moon is a satellite of earth" is
A
or
B
Earth
C
Sun
D
and