Question

An integer which is not divisible by 2 is called a/an
A. Even number
B. Odd number
C. Prime number
D. Composite number

Answer 1

Hint: Numbers can be of different types, such as integers, natural numbers, whole numbers, odd or even numbers, prime numbers, composite numbers, rational numbers etc. There are two different classes of numbers: the first is odd or even numbers and another class is prime or composite numbers.
Even numbers are those numbers which are divisible by 2. Numbers whose unit place is 0, 2, 4, 6, 8 are divisible by 2. Even numbers leave no remainder when divided by 2.
Odd numbers are those numbers which are not divisible by 2. They have 1, 3, 5, 7, 9 at their unit place. Odd numbers leave 1 as a remainder when divided by 2.
Even number can be written in the form of $\left( {2n} \right)$, whereas, every odd number can be written in the form of \[(2n - 1){\text{ }}or{\text{ }}(2n + 1)\], where n is a natural number.
Composite numbers are those natural numbers which have more than two factors.
Prime numbers are those numbers which have exactly two factors, i.e. 1 and the number itself. Every prime number is an odd number except number 2.

Complete step by step solution: Integers which are not divisible by 2 are called odd numbers. E.g. 1, 3, 5, 7 etc.
Hence, option (B) is correct.

Note: Some important points:
A. 1 is neither a prime nor a composite number.
B. 2 is the only even prime number. It is the smallest prime number.
C. Not all odd numbers are prime numbers.
D. All composite numbers can be written as products of prime numbers.