Question

The number which is neither prime nor composite is .......
(A) 0
(B) 1
(C) 2
(D) 5

Answer 1

Hint: For the given question first of all we will have to know about the prime and composite number very clearly. Prime number is the number which is only divided by 1 and the number itself whereas the composite number is the number which is divided by at least one number other than itself.

Complete step-by-step answer:

Let's see few more details about prime numbers and composite numbers for better understanding.
Prime numbers are those numbers that have only two factors, which are 1 and the number itself. 

For example, if we consider a number 19, we know that the only factors it has are 1 and 19, so 19 will be a prime number. 

Composite numbers are those numbers that have more than 2 factors including 1 and the number itself. So, for example, if we consider a number 9, then we know that it has a total of three factors - 1, 3 and 9. So we get that 9 is a composite number. 

Now, we know the concept of prime number and composite number very clearly.
0 has infinite factors as any number multiplied with 0 gives the result as 0. Also as per the definition, we know that prime and composite numbers are positive. We consider 0 as null or neither positive nor negative. So, 0 cannot be a prime or composite number.
1 has only one factor, which is itself. It doesn't satisfy the definition of both prime and composite numbers, so it cannot be a prime or composite number.
So on this basis we can easily say that “0” and “1” are neither prime nor composite. Therefore, the correct options of the given question is option (A) and (B).

Note:  

> Remember the properties about the prime and composite numbers because it will help you a lot in these types of questions. 

> Also remember the fact about the number is that any whole number which is greater than 1 is either prime or a composite number. 

> Composite numbers are said as composite because the meaning of composite is “made by combining”. $4$ is the Least composite number.

> A prime number can also be defined as a number which can not be made by multiplying another whole number. 

> $2$ is the only even prime number and it is the least of all prime numbers.  Except $2$ remaining all prime numbers are odd. 

> The number $5$ given in option (D) is also a prime number.