Your options C and D are the same, but it is true that 51 is a composite number.
ANSWER: One is not a composite number.One is not also a prime number.
1 is neither a prime nor a composite number because it has only one factor (itself (1)). The definition of a prime number is a number that has the factor of one and itself, so one is not prime. The definition of a composite number is a number that has more than 2 factors, so one is not composite. One is a special number.
Composite
Because if they have one or more factores
One (1) is not a composite number.
Your options C and D are the same, but it is true that 51 is a composite number.
ANSWER: One is not a composite number.One is not also a prime number.
1 is neither a prime nor a composite number because it has only one factor (itself (1)). The definition of a prime number is a number that has the factor of one and itself, so one is not prime. The definition of a composite number is a number that has more than 2 factors, so one is not composite. One is a special number.
4 is the least one digit composite number
Composite
A composite number is basically one that is NOT a prime - a composite number is a product of two or more primes.
Composite A prime number is a number that has only two factors (itself and one) A composite number is a number that has more than two factors.
Because if they have one or more factores
21 is composite number because it has more than one number that goes into it
219 is a composite number. This is because composite numbers are any number that has more than two factors(one and itself). Therefore, since 3 and 73 are factors of 219 that makes it a composite number.
391 is a composite number. 391 = 17 * 23 A prime number is a whole number that only has two factors which are itself and one. A composite number has factors in addition to one and itself.