Question

Which of the following numbers is composite?

7
11
15
17

Answer 1

15 is the composite number

Answer 2

A prime number is a number that has no factor other then itself and one (1,2,5, etc.). A composite number is a number that has more then two factors (4,8,16 etc.). The composite number is 15 because it has more then two factors its factors are 1,3,5, and 15.