Question

Choose the incorrect statements.

• A. $1$ is a prime number
• B. All the even numbers are not prime numbers
• C. Numbers of prime numbers between $1$ and $20$ are $8$
• D. None of the above.

Answer 1

Answer: (A), (B)

All the even numbers are not prime numbers

$\underset{–}{option\left(a\right)}$: it is wrong statement because $1$ is neither prime nor composite.
$\underset{–}{option\left(b\right)}$: This statement is wrong because $2$ is the smallest even prime number. So, correct statement will be all even numbers except $2$ are not prime numbers.
$\underset{–}{option\left(c\right)}$: This is correct statement. Prime numbers between $1$ and $20$ are $2,3,5,7,11,13,17$ and $19$. Which counts $8$.