Final answer:
A prime number has no positive divisors other than 1 and itself, while a composite number has at least one positive divisor other than 1 and itself. The number 16 and 27 are composite, while the number 13 is prime.
Step-by-step explanation:
To identify whether a number is prime or composite, we need to understand the definitions of these terms.
A prime number is a positive integer greater than 1 that has no positive divisors other than 1 and itself.
On the other hand, a composite number is a positive integer greater than 1 that has at least one positive divisor other than 1 and itself.
a. The number 16 is composite because it has divisors other than 1 and 16, such as 2, 4, and 8.
b. The number 27 is composite because it has divisors other than 1 and 27, such as 3 and 9.
c. The number 13 is prime because its only divisors are 1 and 13.