Question

Which of the following is not a composite number?
A. 4
B. 6
C. 7
D. 8

Answer 1

Hint: Composite number has more than two factors, which means apart from getting divided by 1 number and itself, It can also be divided by at least one integer or number.

Complete step by step solution:
We can write prime factors of 4 as below:

4 is a Composite number because it can be divided by 1, 2 and 4. So, the number has three factors.

We can write prime factors of 6 as below:

6 is a Composite number because it can be divided by 1, 2 ,3 and 6. So, the number has four factors.

We can write prime factors of 8 as below:

8 is a Composite number because it can be divided by 1 ,2,4 and 8 itself. So, the number has four factors.

We can write prime factors of 7 as below:

Hence 7 is a prime number because it has only two factors 1 and 7 itself. So 7 is not a composite number.

Note: Product of factors does not necessarily distinct means when we multiply factors we should get the original number as it is. We don't consider number 1 as a Composite number.