The number which is neither prime nor composite is –
(A) 0
(B) 1
(C) 2
(D) 5
Answer: B) 1
Explanation:
A prime number is a number that can be divided by only itself and 1. A composite number is a number that can be divided by more than one and itself. The first ten prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29. The first ten composite numbers are 4, 6, 8, 9, 10, 12, 14, 15, 16 and 18.
1 is not a prime number because it can not be divided by any other integer except for 1 and itself. The only factor of 1 is 1. On the other hand, 1 is also not a composite number because it can not be divided by any other integer except for 1 and itself. In conclusion, the number 1 is neither prime nor composite.
2 is the smallest prime number. It can only be divided by 1 and 2. Factors 2 are 1 and 2.
3 is the smallest odd prime number. It can only be divided by 1 and 3. Factors 3 are 1 and 3.
4 is not a prime number because it can be divided by 2 and 4. Factors 4 are 1, 2, and 4.
5 is a prime number because it can only be divided by 1 and 5. Factors 5 are 1 and 5.
0 is prime. Factors are 1 and 0.
