Lucas says that 15 is both a prime number and a composite number. State whether you agree or disagree with Lucas, and be sure to give a definition of either a prime or composite number to strengthen your argument.

Answer 1

I disagree with Lucas. A prime number is defined as a natural number greater than 1 that has no positive divisors other than 1 and itself. In contrast, a composite number is defined as a natural number greater than 1 that has more than two positive divisors.

The number 15 is not a prime number because it can be divided evenly by 1, 3, 5, and 15. Since it has divisors other than just 1 and itself (specifically, 3 and 5), it qualifies as a composite number. Therefore, 15 is a composite number but not a prime number.